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Measurement of Exterior Noise Produced by Aircraft Auxiliary Power Units (APUs) and Associated Aircraft Systems During Ground OperationARP1307C (Current)11/26/2025
Test procedures are described for measuring noise at specific receiver locations (passenger and cargo doors, and servicing positions) and for conducting general noise surveys around aircraft. Procedures are also described for measuring noise level and directivity at noise source locations to facilitate the understanding and interpretation of the data. Requirements are identified with respect to instrumentation; acoustic and atmospheric environment; data acquisition, reduction and presentation, and such other information as is needed for reporting the results. This document makes no provision for predicting APU or component noise from basic engine characteristics or design parameters, nor for measuring noise of more than one aircraft operating at the same time. No attempt is made to suggest acceptable levels of noise or suitable subjective criteria for judging acceptability. ICAO Annex 16 Volume I Attachment C provides guidance on recommended maximum noise levels.
A-21 Aircraft Noise Measurement Aviation Emission Modeling
Understanding the Aero-mechanical Behavior of a MGB Cooling FanF-0081-2025-02445/20/2025
The oil cooling fan of a Main Gearbox (MGB) is a mechanically-driven component whose purpose is to force an air flow through an air cooled oil cooler; its performance is crucial in ensuring that the MGB oil temperature does not exceed a predefined threshold, set to alert the crew in case of an abnormal situation. The design and the certification of a cooling fan is a process involving several steps and multiple disciplines; mechanical design, aerodynamic analysis, dedicated tests carried out both on rigs and at aircraft level need to be exploited as complementary tools to assess the correct aero-mechanical behavior of the system. The aerodynamic assessment is associated to performance, measured in terms of MGB oil temperature: considering a comparison between two cooling fans, one outperforms the other if the resultant MGB oil temperature is lower, keeping the same boundary conditions (engine torque, wind speed, ambient temperature, etc.). The correct mechanical behavior is instead associated to multiple requirements that need to be satisfied: target fatigue life, high and low temperature limits, blade loss containment, maximum speed, etc. The process connecting the very first blank page to the certification of the part is usually linear and well defined, and the experience gathered by Leonardo Helicopters over the years has allowed to follow this path easily in most cases. This paper discusses an intriguing situation: the goal of the activity herein discussed was to replace an obsolete oil cooling fan with a new one. The latter was expected to outperform the first both from the aerodynamic point of view (i.e. lower MGB oil temperature) and from the mechanical point of view (i.e. longer life). The preliminary CFD analyses and the rig tests proved that the new fan was able to outperform the legacy one in regards of the aerodynamic requirement; nevertheless, during the last steps of verification carried out at aircraft level, the installation of the new fan resulted in a higher MGB oil temperature. This triggered dedicated troubleshooting: a sequence of investigative tests performed by means of dedicated rigs, targeted at properly identifying the aerodynamic operative point of the cooling fan and at understanding the reason behind the unexpected outcomes obtained. The relevance of this contribution does not lie in the description of the certification process per se, rather in the nonlinear dynamics characterizing the test sequence once the flight activities pointed out an unpredicted behavior.
Sangiovanni, Andrea, Scaltritti, Diego, Podda, Daniele, Pisani, Paolo, Sartori, Sergio, Alari, Lorenzo
Effect of Gust on Coaxial Rotors using Free Vortex MethodsF-0080-2024-12625/7/2024
The current work focuses on understanding the aerodynamics of a single and coaxial rotor in hover subjected to 1-minus-cosine gust profiles. The work was performed using an in-house free-vortex method that includes the contribution of unsteady aerodynamic terms using the Duhamel integral. Studies were conducted on the Harrington single and coaxial rotor systems trimmed to CT /σ = 0.1, with the gust duration varying from 1-50 revolutions of the rotor, i.e., 0.3 - 15 seconds. Gust amplitudes were also varied from 0.1ωR-0.3ωR. Results were analyzed in terms of the deviation of thrust from the hover values, the frequency content of this signal, angle of attack variations across the span, and the structure of the wake as the system goes through the gust event. It was noted that for single and coaxial rotors, edgewise gusts result in higher frequency components being present in the thrust compared to the axial gust. Large changes in the angle of attack were observed, which could potentially lead to vibratory loads on the system as it experiences the gust. Additionally, an in-house experimental setup consisting of a 3 x 3 fan array and a single rotor (12-inch APC propeller) mounted on a load cell was used to obtain preliminary results of a single rotor operating under gust. The same was compared against the developed numerical method.
Narayanan, Shrivathsan, Govindarajan, Bharath, Chandel, Aaditya
Modeling Activities of Propulsion System Engine Installation SurveyF-0080-2024-13525/7/2024
The multi-role utility helicopter T625 GÖKBEY is designed by Turkish Aerospace and it is equipped with a pair of two-spool CTS800-4AT turboshaft engine developed by Light Helicopter Turbine Engine Company (LHTEC). Components of the cowlings, intakes and exhausts were designed with supplementing CFD analyses and performance of various alternatives were evaluated. Final designs were achieved based on the helicopter performance and engine limits. In order to verify the estimated engine installed performance in design phase, performance of the instrumented engine with its integrated equipment on the platform is examined using flight test data. This paper focuses on the CFD simulations based performance predictions of the air induction system, exhaust system, and IPS blower exhaust. A comprehensive study is assessed to create more realistic models by using flight test data.
Sancar, Emre, Ezertaş, Ahmet Alper, Bayat, Akay, Çakıroğlu, Taylan, Daldal, Abdurrahman Burak
Self-Propelled Sweepers and Scrubbers Tank and Hopper Capacity RatingJ1793_202111 (Current)11/9/2021
This SAE Standard applies to self-propelled sweepers and scrubbers as defined in SAE J2130-1 and J2130-2.
MTC2, Sweeper, Cleaner, and Machinery
Innovative Control and Monitoring Algorithms and Strategies Based on Judicious Functional Partitioning and Frugal Engineering Concepts2021-01-01244/6/2021
As embedded electronic control systems are increasingly penetrating vehicle subsystems, the designers are faced with a dilemma of providing state of art vehicle features on one hand and ensuring frugal implementation of the same to meet competitive pressures on the other. For embedded software and hardware systems this means adoption of judicious and innovative design choices with reusable building blocks. This paper dwells upon various design aspects of control and monitoring which are frequently used for automotive applications such as feed-forward and proportional integral control, diagnostics for sensor boundary conditions, handling of intermittent faults without causing nuisance to the vehicle users etc.
Vaidya, Vishwas Manohar
6.0.120 - Investigation of the Applicability of Numerical Noise Prediction of an Axial Vehicle Cooling FanSAE-PP-002752/4/2021
This paper focuses on the applicability of numerical prediction of sound radiation caused by an axial vehicle cooling fan. To investigate the applicability of numerical methods, a hybrid approach is chosen where first a CFD simulation is performed and the sound radiation is calculated in a second step. For the acoustic simulation an integral method described by Ffowcs-Williams-Hawkings is used to predict the sound propagation in the far-field. The simulation results are validated with experiments. The corresponding setup in experiments and simulation represents an overall system which includes the cooler, the cooling fan and a combustion engine dummy. To optimize the economical applicability in terms of simulation setup and run time, different approaches are investigated. This includes the simulation of only one blade using a periodic boundary condition as compared to the whole fan geometry. In the CFD simulation an SAS-turbulence-model is applied. The results show that this is a very useful approach considering the challenges in prediction of numerical sound. On the one hand, the turbulence model has to solve small scales which cause sound in high frequency ranges which leads to a small time increment and a high grid resolution. On the other hand, a long simulation time for predicting sound in low frequency ranges is needed. Additional to the sound propagation in the far-field, it is a benefit to be able to localize the acoustic sources with regards to geometrical optimization. For this, the divergence of the Lighthill Tensor is calculated on the CFD grid.
Mutagaana, Festo
Enhancement and Validation of VPM-Derived State-Space Inflow Models for Multi-Rotor SimulationF-0076-2020-1628710/5/2020
State-space inflow models have long been the standard for rotor wake modeling for flight dynamics and control simulation. As rotorcraft design continues to trend toward Future Vertical Lift (FVL) multi-rotor configurations in order to overcome the limitations of traditional design, the use of state space inflow models must similarly evolve to capture the complex aerodynamic interactions inherent to these new rotorcraft configurations. There is a demand for a state-space inflow model that accurately captures the significant aerodynamic interactions that occur between multiple rotors, ducted fans, wings, and complex airframes that preexisting inflow formulation fails to address. This paper discusses the ongoing effort to establish a robust methodology for deriving a state-space inflow model suitable for FVL applications from first-principle based viscous Vortex Particle Method (VPM) using the CIFERR system identification tool. The paper focuses on areas of enhancement that expand the identified inflow model's accuracy and usefulness as a tool for flight dynamics simulation of multi-rotor configurations. First, the effects of wake distortion due to rotor tip-path plane (TPP) rotation are thoroughly investigated for a co-axial configuration across a number of airspeeds and implemented into the inflow model formulation for improved simulation accuracy. Next, the rotor interference on the aerodynamic surfaces and the fuselage is explored, with attention placed on addressing this interference as a unified formulation. For the rotor interference on fuselage (3-D body) estimation, investigation of improvement through multi-point sampling is performed. The paper also examines the control design application through constructing the linear time invariant aircraft model with integrated state-space inflow model and verifying the accuracy of gain and phase margins and crossover frequencies. For each of these areas of investigation, the impacts on precision flight dynamics simulation are assessed through frequency and time domain response analysis and comparison to the simulation with first principle based VPM. The validation results of the predicted response data show excellent agreement with VPM simulation and further justify this method of inflow model identification as an effective tool for multi-rotor and FVL applications.
Gladfelter, Matthew, Tischler, Mark, Juhasz, Ondrej, He, Chengjian, Chang, Chongseok, J., Mark
Numerical Study of Distributed Variable Geometry Ducted Fans for eVTOLsF-0076-2020-1648210/5/2020
The effects of key design parameters of tilting distributed ducted fans are investigated through steady-state CFD simulations to assess the benefits of using variable geometry ducts in urban air mobility applications. The analysis is made on three adjacent ducted fans mounted at the trailing edge of a semi-span wing. The fans are represented by body forces calculated using the blade element theory. The duct expansion ratio, the duct thickness and the fan design expansion ratio are varied along with the fan speed, the crosswind speed in hover and the airspeed in forward flight. For each combination of the parameters, the hover Figure of Merit and crosswind stall speed as well as the forward flight lift coefficient, thrust coefficient and propulsive efficiency are evaluated. From these results, variable geometry ducted fans are benchmarked against fixed geometry ducted fans using a simplified 1 hour mission with 10% of hover time. It is found that a ducted fan equipped with a Krueger flap and a variable expansion ratio diffuser consumes nearly 11% less energy to complete the mission.
Marois, Francis, Picard, Mathieu, Rancourt, David
Experimental Analysis of a Multiple Radiator Cooling System with Computer Controlled Flow Rates2020-01-09444/14/2020
The automotive cooling system configuration has remained fixed for many decades with a large radiator plus fan, coolant pump, and bypass valve. To reduce cooling system power consumption, the introduction of multiple computer-controlled heat exchangers may offer some benefits. A paradigm shift from a single large radiator, sized for maximum load, to n-small radiators with individual flow control valves should allow fine tuning of the heat rejection needs to minimize power. In this project, a series of experimental scenarios featuring two identical parallel radiators have been studied for low thermal load engine cooling (e.g., idling) in ground transportation applications. For high thermal load scenarios using two radiators, the fans required between 1120 - 3600 W to maintain the system about the coolant reference temperature of 85oC. In contrast at reduced thermal loads, a single radiator configuration with half the heat transfer surface area required between 550 - 1000 W for the same operating conditions. A 51% reduction in fan and pump power consumption at a lower thermal load, while maintaining coolant temperature about the setpoint value, offers possibilities on redesigning the thermal management system. Given that vehicles often operate at reduced thermal loads, these findings can help improve the overall powertrain performance.
Syed, Zaker, Wagner, John
Replacing Twin Electric Fan Radiator with Single Fan Radiator2019-28-238111/21/2019
Downsizing is one of the crucial activities being performed by every automotive engineering organization. The main aim is to reduce - Weight, CO2 emissions and achieve cost benefit. All this is done without any compromise on performance requirement or rather with optimization of system performance. This paper evaluate one such optimization, where-in radiator assembly with two electric fan is targeted for downsizing for small commercial vehicle application. The present two fan radiator is redesigned with thinner core and use of single fan motor assembly. The performance of the heat exchanger is tested for similar conditions back to back on vehicle and optimized to get the balanced benefit in terms of weight, cooling performance and importantly cost. This all is done without any modification in vehicle interface components except electrical connector for fan. The side members and brackets design is also simplified to achieve maximum weight reduction. Further Cooling system performance of engine is evaluated along with Fuel efficiency; results are compared with present configuration.
Bhargava, Aashish, Soni, Gaurav, Warkhade, Tushar
Maintenance of Design Voltage - Snowmobile Electrical SystemsJ277_201909 (Current)9/25/2019
This SAE Recommended Practice provides test methods and requirements for maintenance of design voltage in snowmobile electrical systems. It pertains to both battery-equipped and battery-less systems.
Snowmobile Technical Committee
Terahertz Data Links Without Direct Line of SightTBMG-351439/1/2019
Today’s cellular networks and Wi-Fi systems rely on microwave radiation to carry data but the demand for more bandwidth is quickly becoming more than microwaves can handle. That has researchers thinking about transmitting data on higher-frequency terahertz waves, which have as much as 100 times the data-carrying capacity of microwaves. But terahertz communication technology is in its infancy — there is much basic research to be done and plenty of challenges to overcome.
Intelligent Motion Controls for Smarter Air FlowTBMG-348167/1/2019
No longer a trend, automation has become the foundation in technology for manufacturing. This article addresses three areas that require new thinking and innovative approaches for next-generation cooling technology manufacturing: where intelligent motion controls are used, whether they increase product life and performance, and what they protect.
An Experimental Study to Evaluate Hydro-/Ice-Phobic Coatings for Icing Mitigation over Rotating Aero-engine Fan Blades2019-01-19806/10/2019
Ice accretion on aero-engines, especially on the fan blades, is the very hazardous icing incident due to the potential performance degradation of jet-engines. In the present study, an experimental investigation was conducted to examine the performance of ice-phobic coatings for jet-engine fan icing mitigation. The experimental study was performed in the unique Icing Research Tunnel at Iowa State University (ISU-IRT) with a scaled engine fan model operated under wet glaze and dry rime ice conditions. To evaluate the effects of anti-icing coatings and to acquire the important details of ice accretion and shedding process on fan blade surfaces, a “phase-locked” imaging technique was applied with a high-resolution imaging system. The power input required to drive the engine fan model rotating at a constant prescribed speed was also measured during the ice accretion experiment. It was found that both super-hydrophobic surface (SHS) and ice-phobic coating have its advantage in engine anti-icing. SHS facilitated the blades surface with much less ice, under both glaze icing and rime icing conditions, while ice-phobic coating prevents the large ice chunk formed in the leading edge as the ice chunk easily shed from the leading edge, compared with SHS blade and blades with a hydrophilic coating. Meanwhile, ice accreted on fan blades was also found to result in the degradation of the engine performance as the required power input to drive the engine fan model increased significantly as the ice accreted on the fan blades. To fully investigate power consumption, all blades are painted with SHS. The test results show that all the blades surface are nearly ice-free and the power consumption remains at a lower level compared with the situation all blades without coating treatment.
Tian, Linchuan, Liu, Yang, Li, Linkai, Hu, Hui
Simulation of Ice Particle Breakup and Ingestion into the Honeywell Uncertified Research Engine (HURE)2019-01-19656/10/2019
Numerical solutions have been generated which simulate flow inside an aircraft engine flying at altitude through an ice crystal cloud. The geometry used for this study is the Honeywell Uncertified Research Engine (HURE) which was recently tested in the NASA Propulsion Systems Laboratory (PSL) in January 2018. The simulations were carried out at predicted operating points with a potential risk of ice accretion. The extent of the simulation is from upstream of the engine inlet to downstream past the strut in the core and bypass. The flow solution is produced using GlennHT, a NASA in-house code. A mixing plane approximation is used upstream and downstream of the fan. The use of the mixing plane allows for steady state solutions in the relative frame. The flow solution is then passed on to LEWICE3D for particle trajectory, impact and breakup prediction. The LEWICE3D code also uses a mixing plane approximation at the boundaries upstream and downstream of the fan. A distribution of particle sizes is introduced upstream, based on the distribution measured during the test. Predicted collection efficiency and melt ratio results are presented on various surfaces. The redistribution of particle sizes and mass are also investigated at various axial locations and compared to particle measurements in the bypass.
Rigby, David L., Wright, William, Flegel, Ashlie, King, Michael
Design and Experiment on Aircraft Electromechanical Actuator Fan at Different Altitudes and Rotational Speeds01-12-01-00036/7/2019
For electromechanical actuators (EMAs) and electronic devices cooling on aircraft, there is a need to study cooling fan performance at various altitudes from sea level to 12,000 m where the ambient pressure varies from 1 to 0.2 atm. As fan static pressure head is proportional to air density, the fan’s rotational speed has to be increased significantly to compensate for the low ambient pressure of 0.2 atm at the altitude of 12,000 m. To evaluate fan performance for EMA cooling, a high-rotational-speed, commercially available fan made by Ametek with a diameter of ~82 mm and ~3 m3/min zero-load open cooling flow rate when operating at 20,000 rpm was chosen as the baseline. According to fan scaling laws, this fan was expected to meet the cooling needs for an EMA when operating at 0.2 atm. Using a closed flow loop, the performance of the fan operating in the above ambient pressure range and at a rotational speed between 15,000 and 30,000 rpm was evaluated. Unexpectedly, at 0.2 atm, the Ametek fan was able to produce only about one-third of the static pressure head predicted by the fan scaling laws at a flow rate of 1 m3/min. The purpose of the present effort is to modify the Ametek design by using a standard optimization procedure with the aid of computational fluid dynamics (CFD). The final blade designs were manufactured by three-dimensional (3D) printing. The results and performances of these fan designs were confirmed experimentally which showed the new designs meet the cooling requirements by providing the necessary static pressure head and flow rates at the low ambient pressure of 0.2 atm. It is concluded that the new blade designs are able to yield a much better performance over the ranges of altitudes and rpm for aircraft EMA cooling. Thus, this study establishes a sound blade design method which can reduce the cost associated with expensive experimental investigation by using CFD tools.
Wu, Wei, Lin, Y.R., Gyasi, E., Kizito, J.P., Leland, Q.H., Chow, L.C.
Fuel Efficiency Technology Impact on Radiator Thermal Durability2019-01-04984/2/2019
With the increasing stringency of emission regulations, auto makers are now improving vehicle fuel efficiency via all kinds of technologies, such as hybrid systems, turbocharged or supercharged engines, engine auto start/stop, active grille shutters, etc. By implementing a variety of technologies, the engine cooling module’s working environment and work load has changed. This paper will mainly focus on the impact to the thermal durability of the engine cooling module’s main radiator from active grille shutter and electric thermostat implementation. A 2017MY hybrid vehicle using the above technology is evaluated by a wind tunnel test at a variety of ambient temperatures and driving conditions. First, such technologies’ control logic is studied by the wind tunnel test, so that the evaluation condition for evaluating the radiator’s thermal stress can be properly chosen to represent the actual field usage. Then, a single variable method is used to understand the difference in thermal damage mechanism between traditional and new technology conditions, as well as quantify the impact on radiator thermal damage for active grille shutters and electrical thermostat individually. Lastly, such understanding of the mechanism and quantified damage difference can be utilized to evaluate if the radiator thermal durability is adequate for the field when there are vehicle model changes.
Tian, Yilin
Ruggedizing Commercial-Grade Computers into MIL-Hardened Systems19AERP02_012/1/2019
As performance capabilities for embedded computing products expand, the requirements for commercial-grade and MIL ruggedized systems blur into similar specifications. There are increasing demands to take feature-rich, successful industrial/commercial enclosure systems into MIL or other harsh environment applications. Similarly, engineers are designing up-front computing platforms that they can expand into harsher environments.
Fan Guard for Off-Road MachinesJ1308_201901 (Current)1/10/2019
This practice applies to guarding of engine cooling fans used on Off-Road Self-Propelled Work Machines defined in SAE J1116. It does not include guarding for belts, pulleys, or other rotating equipment used on these machines.
OPTC1, Personnel Protection (General)
Ricocheting Radio Waves Monitor the Tiniest MovementsTBMG-336131/1/2019
Infrared motion detectors can cover only a limited amount of space, a person has to be within the detector's line of sight to be detected, and lights can go off when a person remains still for too long. Work has demonstrated that patterns made by radio waves can detect a person's presence and location anywhere inside a room. A new motion sensor based on metamaterials is sensitive enough to monitor a person's breathing.
Thinking Ahead Thermally: A Guide to Thermal Management Considerations for Medical Devices, Part 2TBMG-335711/1/2019
As the medical device and engineering industry grows, there is also demand for better devices and equipment. Trends such as smaller and more powerful electronics, as well as increased focus on improved customer experience, affect the medical device industry as much as any other. Medical devices, though, also need to be portable, and their costs must be judiciously managed. Above all, reliability is crucial.
Radiator NomenclatureJ631_201810 (Current)10/9/2018
This SAE Recommended Practice documents nomenclature in common use for various types of radiator and radiator core construction, as well as for various radiator-related accessories.
Cooling Systems Standards Committee
Novel Turboelectric Aircraft DesignTBMG-288615/1/2018
NASA Langley Research Center has developed a novel aircraft design that can carry 150+ passengers over a range of 3,500 nautical miles. Key features include a turboelectric propulsion system, twin underwing turbofans, and a rear-fuselage, electrically driven, boundary layer ingesting fan. The design is developed for single-aisle-class aircraft (the largest commercial transport class in the world) to significantly reduce fuel burn compared to current aircraft.
Analytical Investigation of Fan Shroud on a Thermal Heat Exchanger for Automotive Applications2017-28-19517/10/2017
Thermal management is one of the most challenging and innovative aspects of the automotive industry. The efficiency of the vehicle cooling framework unequivocally relies upon the air stream through the radiator core. Significant advances in thermal management are being embraced in the field of radiator material and coolant. The radiator shouldn't be exclusively credited for the reliable cooling of the engine. There are other auto parts that play an essential role in keeping engine temperature at a manageable level. The fan-shroud assembly is an important component of the cooling system. While the fan is responsible for drawing in air, the fan shroud's job is to ensure uniform air distribution to the radiator core. By assisting airflow in the engine compartment the fan shroud helps in dismissing excess heat from the engine. This assembly also prevents the recirculation of heated air through the cooling fan. This paper endeavors to bring forth a new design and an improvement in the cooling system ubiquitous in the new era of modern engineering. An iterative process has been undertaken to develop an effective shroud design which has been validated with the virtual results on a standardized radiator with quantified thermal properties. SolidWorks has been used for modelling while meshing and CFD Analysis has been performed in FLUENT Environment. A uniform pressure distribution was observed across the face of the radiator core which expanded the proficiency of the radiator and hence attaining a notable increase in heat dismissal when contrasted to a radiator without a fan- shroud combination. These results can be used to moderate the dimensions of the radiator for compact packaging.
Gopal, K Nantha, Ashok, B., Bahuguna, Rishabh, Prasad, Tanmay
Fan Noise Prediction for Off-Highway Vehicle2017-01-18346/5/2017
Fan noise can form a significant part of the vehicle noise signature and needs hence to be optimized in view of exterior noise and operator exposure. Putting together unsteady CFD simulation with acoustic FEM modeling, tonal and broadband fan noise can be accurately predicted, accounting for the sound propagation through engine compartment and vehicle frame structure. This paper focuses on method development and validation in view of the practical vehicle design process. In a step by-step approach, the model has been validated against a dedicated test-set-up, so that good accuracy of operational fan noise prediction could be achieved. Main focus was on the acoustic transfer through the engine compartment. The equivalent acoustic transfer through radiators/heat exchangers is modeled based on separate detailed acoustic models. The updating process revealed the sensitivity of various components in the engine compartment. Unsteady CFD included the build-up of a sliding mesh model which was analyzed using the DDES method. After convergence, time data of blade surface pressure were exported in CGNS format. These pressure data were used to generate rotating dipole sources in acoustic FE analysis and predict the fan noise response in frequency domain at two selected rpm. Post processing includes the predicted noise at target microphone positions as well as colormaps of sound pressure distributions that can guide to the development of countermeasures.
von Werne, Dirk, Chaduvula, Prasanna, Stahl, Patrick, Jordan, Michael, Huber, Jamison, Kucukcoskun, Korcan, Niculescu, Mircea
Rugged Smart DisplaysTBMG-271806/1/2017
General Micro Systems, Inc. Rancho Cucamonga, CA 800-307-4863
Cormorant Fancraft UAS: Internal Rotor Technology MaturingF-0073-2017-122955/9/2017
ABSTRACT Fancraft™ configurations have been attempted with varying degrees of success with the Piasecki ducted fan 'AirGeeps' back in the 1960s the most notable. Technical challenges tabled these vehicles at the time in favor of open rotor (helicopter) aircraft designs. Urban Aeronautics Ltd (UA) was formed in 2000 to pursue the development of compact, internal rotor configurations that addressed the earlier challenges of Fancraft™. Tactical-Robotics Ltd (TRL) is a wholly owned subsidiary of UA focused primarily on the development of military and homeland security variants of Fancraft™ including unmanned platforms. The Cormorant is a multirole UAS platform capable of a wide range of missions into complex, obstacle ridden terrain. In flight testing since 2010, it has achieved a TRL of 5. These test results have confirmed that earlier 'AirGeep challenges' have been addressed and expected performance goals have been substantiated thus far. Fancraft™ have proven viable and future testing will focus on the cruise flight regime and more advanced levels of autonomy with the goal of attaining a TRL level 6 in the next phase of testing.
Yoeli, Rafi, Traeger, Yitzchak
State-Space Inflow Model Identification from Viscous Vortex Particle Method for Advanced Rotorcraft ConfigurationsF-0073-2017-121035/9/2017
ABSTRACT This paper describes the methodology that identifies a state-space rotor induced inflow model from first-principle based viscous Vortex Particle Method (VPM) simulation for flight dynamics and control applications. Modern advanced rotorcraft configurations usually involve multiple rotors (e.g., co-axial), fans, wings, etc. where the aerodynamic interaction can be significant under certain flight conditions. The paper presents a unified state-space inflow formulation that addresses the aerodynamic interaction that is well suited for flight dynamics analysis and control design applications. In implementation, the unified inflow model is derived through system identification using VPM simulation generated data. The usage of first-principle based VPM provides a solid approach in capturing important rotor wake physics. This includes both the wake distortion and wake diffusion that are essential for an accurate interactional wake solution, without relying on empirical modeling parameters (e.g., vortex core size and wake dissipation parameters, etc.). The methodology of inflow model identification was first validated with a single rotor where measured data are available. Good agreement of the identified model response with the measurements was obtained. The methodology was further evaluated with a co-axial rotor system. Excellent correlation of the identified model with original VPM simulation was also obtained in both hover and forward flight.
He, Chengjian, Tischler, Mark, Syal, Monica, Juhasz, Ondrej
Musclecar Godzilla: Dodge Reveals 840-hp Challenger SRT Demon17AUTP05_125/1/2017
After months of teasing and a high-profile tie-in with the Fast & Furious film franchise, at the New York auto show FCA's Dodge division revealed its 2018 Challenger SRT Demon, a drag racer-in-street-clothes featuring an 840-hp variant of the now-famous 6.2-L supercharged OHV V-8 that the company boldly claimed makes the Challenger Demon the quickest production car in the world. Revealing the Demon at an event on the eve of the 2017 New York auto show, Tim Kuniskis, head of passenger cars- Dodge, SRT, Chrysler and FIAT, for FCA North America, catalogued the Demon's list of claimed firsts or record-setting accomplishments, most delivered by the car's heavily-revised Hemi V8. Kuniskis said the Demon is the world's fastest production vehicle to accelerate through the quarter mile, doing so in 9.65 s at a trap speed of 140 mph (225 km/h); the industry-standard metric of 0-60 mph (97 km/h) acceleration is dispatched in 2.3 s, which he claimed also is the world's best, although that figure is bound to be disputed.
Visnic, Bill
Calibration and Demonstration of Vehicle Powertrain Thermal Management Using Model Predictive Control2017-01-01303/28/2017
Control of vehicle powertrain thermal management systems is becoming more challenging as the number of components is growing, and as a result, advanced control methods are being investigated. Model predictive control (MPC) is particularly interesting in this application because it provides a suitable framework to manage actuator and temperature constraints, and can potentially leverage preview information if available in the future. In previous SAE publications (2015-01-0336 and 2016-01-0215), a robust MPC control formulation was proposed, and both simulation and powertrain thermal lab test results were provided. In this work, we discuss the controller deployment in a vehicle; where controller validation is done through road driving and on a wind tunnel chassis dynamometer. This paper discusses challenges of linear MPC implementation related to nonlinearities in this over-actuated thermal system. Specifically, the fan and grill shutter actuators have a nonlinear influence on the individual airflows through the charge air cooler and radiator heat exchangers, and the design choices in dealing with these nonlinearities affects the control performance and controller memory requirements. The memory requirements of the resulting controller are also analyzed and compared to other MPC controllers.
Bonkoski, Phillip, Karnik, Amey Y., Fuxman, Adrian
Fan Shroud Design for Low Speed Damageability2017-01-13003/28/2017
An engine cooling system in an automotive vehicle comprises of heat exchangers such as a radiator, charge air cooler and oil coolers along with engine cooling fan. Typical automotive engine-cooling fan assembly includes an electric motor mounted on a shroud that encloses the radiator core. One of main drivers of fan shroud design is Noise, Vibration, and Harshness (NVH) requirements without compromising the main function of airflow for cooling requirements. In addition, there is also a minimum stiffness requirement of fan shroud which is often overlooked in arriving at optimal design of it. Low Speed Damageability (LSD) assessment of an automotive vehicle is about minimizing the cost of repair of vehicle damages in low speed crashes. In low speed accidents, these fan motors are subjected to sudden decelerations which cause fan motors to swing forward thereby damaging the radiator core. So designing fan shroud for low speed damageability is of importance today. In this paper, the design development of fan shroud using CAE and testing has been illustrated. Lack of sufficient stiffness of the fan shroud has been identified as the source to cause damage to radiator in a vehicle low speed crash test. In addition to vehicle level simulations used to guide the fan shroud design, this paper describes how a sub system level simulations and testing under low speed impact loading conditions can be used to predict contact between fan motors mounted on fan shroud and radiator. Also a generic pulse representing low speed impact conditions up to 16 km/h has been recommended as the loading pulse. Finally, an effective design guideline has been proposed as a requirement in designing a fan shroud to eliminate damage due to inertial movement of fan motors in low speed impacts.
Jayachandran, Raj, Alavandi, Bhimaraddi, Niesluchowski, Matt, Low, Erika, Miao, Yafang, Zhang, Yi
Experimental Investigation of the Impact of Nanofluids on Heat Transfer Performance of a Motorcycle Radiator2017-01-16113/28/2017
In the present work, the effect of various nanofluids on automotive engine cooling was experimentally studied. Al2O3, TiC, SiC, MWNT (multi-walled nanotube), and SiO2 nanoparticles with average diameter ranging between 1 and 100 nm were mixed with distilled water to form nanofluids. An ultrasonic generator was used to generate uniform particle dispersion in the fluid. A compatibility test was carried out on all nanofluids and it was found that TiC, MWNT, and Si3N4 nanoparticles settled and separated from the fluid within 3 hours after preparation. The engine cooling performance testing setup consisted of an Aprilia SXV 450 engine, the nanofluid cooling loop, a radiator, a fan, etc. Thermocouples and resistance temperature detectors (RTD’s) were attached to the inlet and outlet of the radiator hose to monitor the temperature changes taking place in the cooling system. A flowmeter was attached to the inlet hose of the radiator to monitor the coolant flow rate. Results of heat transfer capability were compared for cooling system with and without nanoparticle seeding. It was observed that the heat dissipation capacity of nanofluids increased with increasing volume concentration of nanoparticles and also with increasing coolant flow rate. The results showed that the heat dissipated by TiO2, SiO2 and Al2O3 nanofluids were 31.9%, 27.7% and 12.5% higher than the base fluid, at 3.5 GPM flow rate and at 1% volume concentration of nanoparticles.
Mathivanan, Elankathiravan, Gasior, David, Liu, Liping, Yee, Kingman, Li, Yawen
Thermal Protection of Rear Mounted Engine and Its Components Using a Ventilation Fan with Unique Monitoring and Fault Diagnosis Technique2017-01-06203/28/2017
The engine compartment of passenger car application contains various source which radiates the produced heat and raises the temperature level of the compartment. The rise in compartment temperature increases the body temperature of individual component. The rise in body temperature of critical components can endanger the durability or functionality of the specific component or a system in which it operates. The aim of this paper is to strategize thermal protection of the rear mounted engine and its components of a vehicle having radiator and cooling fan mounted in front. An additional ventilation fan with speed sensor is fitted alongside rear mounted engine and a unique monitoring technique framed in the EMS ECU to protect critical components like HT cables, alternators, ECUs, wiring harness etc. from thermal damage. The EMS continuously monitors the engine speed, vehicle speed and the PWM signal of ventilation fan to ensure the intended operation of the ventilation fan. With the implementation of additional ventilation fan it is observed that maximum engine compartment temperature does not exceed safe operating temperature limit when the vehicle is driven in all road load condition (including highway, city & gradient drive conditions) and in all vehicle operating conditions. Excessive operation at higher compartment temperature unnecessarily causes individual component durability & performance to deteriorate at considerably faster rate. Thus, method of the present disclosure ensures that every component in engine compartment is operating in safe operating limits. In-case any failure occurs in the ventilation fan, newly developed EMS diagnosis strategy identify fault and indicates the problem to the driver through telltale. EMS also restricts the vehicle speed to safely maneuver vehicle to the nearest service center for repair.
Parmar, Chandrakant, Tyagarajan, Sethuramalingam, Tiwari, Sashikant, Thonge, Ravindra, Paul, S Arun
Cooling Your Embedded System: What Can Your Open Standard Architecture Handle?TBMG-264372/1/2017
Embedded computing systems for Mil/Aero applications are often conduction-cooled in an ATR or nonstandard chassis. However, there are many designs that require 19" rackmount systems with forced-air cooling. As more processing performance is packed into tight spaces, enclosures that provide advanced cooling options are increasingly common.
Cooling Your Embedded System17AERP02_022/1/2017
What Can Your Open Standard Architecture Handle? Embedded computing systems for Mil/Aero applications are often conduction-cooled in an ATR or nonstandard chassis. However, there are many designs that require 19″ rackmount systems with forced-air cooling. As more processing performance is packed into tight spaces, enclosures that provide advanced cooling options are increasingly common. The open-standard embedded architectures have different recommended limitations for power. Sometimes these are electrical pinout limitations, and other times they are recommended thermal limitations. There are “tricks of the trade” to extend the power for certain architectures as well as the ability to maximize the thermal limits.
Design Optimization of Automotive Radiator Cooling Module Fan of Passenger Vehicle for Effective Noise Management Using CFD Technique2017-26-01831/10/2017
An automotive radiator cooling fan has been observed to be an important noise source in a vehicle and with increasing noise refinements, the need for a quieter but effective fan is of utmost importance. Although some empirical prediction techniques are present in literature, they are not sufficiently accurate and cannot give a detailed view of the entire noise spectrum and the various noise prone zones. Hence the need for highly accurate Computational Fluid Dynamics (CFD) study is essential to be able to resolve the minute acoustic stress. Large Eddy Simulation technique in CFD is used to resolve the minute scales of motion in the flow as the sound pressures simulated are very small compared to system level pressures and require immense accuracy. Detailed mesh dependency and Y+ studies are conducted to implement higher accuracy as well as keep mesh requirements within computationally feasible zone. The numerical results obtained by the CFD study is corroborated against the test results by comparing the A-weighted Sound Pressure Levels (SPL) spectrum in the frequency domain.
Tare, Kedar, Mukherjee, Uttiya, Vaidya, Rohit J
Effect of Variable Cooling System for Fuel Economy Improvement on Scooter with Air Cooled Engine2016-32-009211/8/2016
A variable cooling system has been developed for scooters equipped with an air cooled, four-stroke, single cylinder gasoline engine. This system opens or closes louver located at the cooling air inlet using an oil-temperature sensitive actuator. When the engine is cold or the engine load is low, the louver shut off the cooling air for a quick warm-up and for maintaining the engine oil temperature high to reduce the friction losses that occur with low oil temperature while eliminating the loss from driving the cooling fan as well. The quick warm-up also decreases supplementary fuel injections necessary when the engine is cold. Consequently, fuel economy improvement by 3.3% was realized in running condition of the Urban Driving Cycle.
Kobayashi, Tomokazu, Kosei, Kazuyuki, Ito, Sadaaki, Iijima, Satoshi
Fan-shroud optimization for enhanced thermal performance16OFHP10_0610/1/2016
CFD helps researchers from Argonne, Cummins and CD-Adapco to maximize cooling air mass flow rates through heat exchangers. Tighter emissions requirements and underhood packing due to higher power demands from engines necessitate more optimized cooling packages. Fan and fan-shroud design is crucial for underhood airflow management. Fan shrouds funnel cooling air, which is sucked by the fan and passed through heat exchangers. Shroud design affects both the airflow and the noise generated by the fan. The vehicle underhood compartment consists of the engine and cooling package. In heavy-duty trucks, the cooling package includes the heat exchanger, fan shroud and fan. To optimize the fan-shroud shape to maximize cooling air mass flow rates through the heat exchangers, researchers from Argonne National Laboratory, Cummins and CD-Adapco used the Adjoint approach to optimization. Adjoint optimization is an efficient sensitivity analysis method for aerodynamic shape and pressure drop evaluation.
Fan Shroud Optimization Using Adjoint Solver2016-01-80709/27/2016
Fan and fan-shroud design is critical for underhood air flow management. The objective of this work is to demonstrate a method to optimize fan-shroud shape in order to maximize cooling air mass flow rates through the heat exchangers using the Adjoint Solver in STAR-CCM+®. Such techniques using Computational Fluid Dynamics (CFD) analysis enable the automotive/transport industry to reduce the number of costly experiments that they perform. This work presents the use of CFD as a simulation tool to investigate and assess the various factors that can affect the vehicle thermal performance. In heavy-duty trucks, the cooling package includes heat exchangers, fan-shroud, and fan. In this work, the STAR-CCM+® solver was selected and a java macro built to run the primal flow and the Adjoint solutions sequentially in an automated fashion. In this analysis, the primal flow provides flow information (e.g. velocity, temperature and pressure) and the Adjoint solver provides surface morphing details w.r.t. max or min of the specified objective function. In the present work, the fan-shroud surface morphing was performed based on the maximum air mass flow rate through the heat exchanger outlet w.r.t. the spatial positions of the fan-shroud surface. An overall 1.4% increase in cooling air mass flow was observed in the heat exchanger with the optimized/morphed fan-shroud surface. The identified main optimized locations were mainly at the sharp edges of the original manufactured fan-shroud. Further evaluation is underway to maximize the cooling air mass flow benefit.
Vegendla, Prasad, Sofu, Tanju, Saha, Rohit, Madurai Kumar, Mahesh, Hwang, Long-Kung, Dowding, Steven
The Research on the Temperature Control Stability of Hydraulic Retarder Oil Based on Organic Rankine Cycle2016-01-80859/27/2016
The hydraulic retarder is an auxiliary braking device generally equipped on commercial vehicles. Its oil temperature change influences the brake performance of hydraulic retarder. The Organic Rankine Cycle (ORC) is a good means to recover exhausted heat. Moreover, it can cool oil and stably control oil temperature with the help of heat absorption related with evaporation. Comprehensively considering the heat-producing characteristics of hydraulic retarder and the temperature control demand, the aimed boundary conditions are determined. Also the changing rules about the working medium flow rate are obtained. In this work, the heat-producing properties of hydraulic retarder under different conditions and the oil external circulating performance is firstly analyzed. By researching the system’s adaptation to the limiting conditions, the aimed temperature to control is prescribed. Then combined with the existing ORC structure, the variation of evaporation temperature and working medium flow rate in the evaporator is disclosed. On the basis, the energy consumption of the pump and the cooling fan is calculated. By comparing the simulation results between the ORC system and the traditional water-cooling system, the temperature control stability, the system energy consumption and the braking torque characteristics of the hydraulic retarder are compared and contrasted. The experiment proves the effectiveness of the oil temperature control by using the ORC system. The results reveal that the ORC system decreases the oil temperature variation by 87% and recovers at least 1kW energy for the vehicle use under the same working condition. Besides it can decrease at most 150N*m braking torque fluctuation. Both the retardant braking stability and the vehicle energy utilization are improved, so the system deserves a future promotion.
Ren, Yanjun, Tan, Gangfeng, Ji, Kangping, Zhou, Li, Zhan, Ruobing
Experimental Study of Hydraulic Retarder Waste Heat Recovery Based on the Organic Rankine Cycle2016-01-80799/27/2016
The hydraulic retarder is an important auxiliary braking device. With merits such as its high braking torque, smooth braking, low noise, long service life and small size, it is widely used on modern commercial vehicles. Transmission fluid of traditional hydraulic retarder is cooled by engine cooling system, which exhausts the heat directly and need additional energy consumption for the thermal management component. On account of the working characteristics of hydraulic retarder, this study designs a set of waste heat recovery system based on the Organic Rankine Cycle (ORC). Under the premise of ensuring stable performance of hydraulic retarder, waste heat energy in transmission fluid is recycled to supplement energy requirements for cooling system. First of all, a principle model, which is scaled down according to D300 retarder`s thermal power generation ration of 1:100, is established. Then through theoretical calculations, components' structural parameters of the ORC are determined. And theoretical model concerning waste heat recovery system based on the ORC is established. Next, through theoretical calculation, the characteristic of waste heat recovery under typical working conditions of hydraulic retarder is determined. What’s more, through simulation of the retarder's working conditions, the waste heat recovery test rig based on the ORC is established. Then, heat recovery characteristic under typical working condition are obtained by analyzing the experimental data. And mathematical model is thus amended. Finally, based on the corrected mathematical model and setting driving conditions, actual effects of total vehicle waste heat recovery system are evaluated. Research shows that the waste heat recovery system can ensure transmission fluid temperature stable from 80 to 120 °C when the hydraulic retarder is working and recover about 6% of the waste heat under the typical working conditions of hydraulic retarder.
Zhang, Zhiwei, Tan, Gangfeng, Yang, Mengying, Yang, Zhongjie, Han, Mengzuo
Electromechanical Actuator Cooling Fan Blades Design and Optimization2016-01-19949/20/2016
For aircraft electromechanical actuator (EMA) cooling applications using forced air produced by axial fans, the main objective in fan design is to generate high static pressure head, high volumetric flow rate, and high efficiency over a wide operating range of rotational speed (1x∼3x) and ambient pressure (0.2∼1 atm). In this paper, a fan design based on a fan diameter of 86 mm, fan depth (thickness) of 25.4 mm, and hub diameter of 48 mm is presented. The blade setting angle and the chord lengths at the leading and trailing edges are varied in their suitable ranges to determine the optimal blade profiles. The fan static pressure head, volumetric flow rate, and flow velocity are calculated at various ambient pressures and rotational speeds. The optimal blade design in terms of maximum total-to-total pressure ratio and efficiency at the design point is obtained via CFD simulation. A 5-blade configuration yields the best performance in terms of efficiency and total pressure ratio. Our designed fan can perform satisfactorily as a cooling fan for EMA by operating at a rotational speed of 8,000∼22,000 rpm and in an ambient environment of 0.2∼1 atm.
Wu, Wei, Lin, Yeong-Ren, Chow, Louis, Gyasi, Edmund, Kizito, John P., Leland, Quinn
Electromechanical Actuator Cooling Fan Reliability Analysis and Safety Improvement2016-01-19979/20/2016
The aircraft electromechanical actuator (EMA) cooling fan is a critical component because an EMA failure caused by overheating could lead to a catastrophic failure in aircraft. Fault tree analysis (FTA) is used to access the failure probability of EMA fans with the goal of improving their mean time to failure (MTTF) from ∼O(5×104) to ∼ O(2.5×109) hours without incurring heavy weight penalty and high cost. The dual-winding and dual-bearing approaches are analyzed and a contra rotating dual-fan design is proposed. Fan motors are assumed to be brushless direct current (BLDC) motors. To have a full understanding of fan reliability, all possible failure mechanisms and failure modes are taken into account. After summarizing the possible failure causes and failure modes of BLDC fans by focusing on each failure mechanism, the life expectancy of fan ball bearings based on a major failure mechanism of lubricant deterioration is calculated and compared to that provided in the literature. The advantages and disadvantages of the three fault-tolerant cases are discussed. Finally, measures to quantify a fan's reliability are recommended and the method to estimate MTTF by Weibull distribution is provided.
Wu, Wei, Lin, Yeong-Ren, Chow, Louis, Gyasi, Edmund, Kizito, John P., Leland, Quinn
Energy Saving Analysis of Vehicle Hydraulic Retarder Thermal Management System Based on Rankine Cycle2016-01-19419/18/2016
Vehicle hydraulic retarders are applied in heavy-duty trucks and buses as an auxiliary braking device. In traditional cooling systems of hydraulic retarders, the working fluid is introduced into the heat exchanger to transfer heat to the cooling liquid in circulation, whose heat is then dissipated by the engine cooling system. This prevents the waste heat of the working fluid from being used effectively. In hydraulic retarder cooling system based on the Organic Rankine Cycle, the organic working fluid first transfers heat with the hydraulic retarder working fluid in Rankine cycle, and then outputs power through expansion machine. It can both reduce heat load of the engine cooling system, and enhance thermal stability of the hydraulic retarder while recovering and utilizing braking energy. First of all, according to the target vehicle model, hydraulic retarder cooling system model based on Rankine cycle is established. Through presetting Rankine cycle parameters, characteristics and power consumption of this cooling system are analyzed under different hydraulic retarder working conditions. Then a mathematical model of traditional hydraulic retarder cooling system is set up. Its characteristics and power consumption under different hydraulic retarder working conditions are analyzed. Next, the effectiveness of the mathematical model of hydraulic retarder cooling system model based on Rankine cycle is verified by experiments. Finally, based on the Rankine cycle model after verification, two cooling systems are compared in cooling capacity, power consumption, economy and volume under the same circumstances. The results show that, in contrast to traditional cooling system of hydraulic retarder, hydraulic retarder cooling system based on the Organic Rankine Cycle, though taking up a little more space, can effectively reduce heat load of engine cooling system, improve thermal stability of hydraulic retarder, lower energy consumption and be more economical.
Wang, Tie, Tan, Gangfeng, Guo, Xuexun, Xiong, Shengguang, Zhang, Zhiwei, Gao, Xin
A Statistically Based Approach to Broadband Liner Design and AssessmentTBMG-251778/1/2016
The broadband component of fan noise has grown in relevance with the utilization of increased bypass ratio and advanced fan designs. Thus, while the attenuation of fan tones remains paramount, the ability to simultaneously reduce broadband fan noise levels has become more attractive. Advanced manufacturing techniques have also opened new possibilities for the implementation of broadband liner concepts. This innovation is an integrated method for the design and evaluation of novel broadband acoustic liner concepts for complex engine configurations.
Computational Aeroacoustics for HVAC Systems Utilizing a Hybrid Approach2016-01-18086/15/2016
We present a recently developed computational scheme for the numerical simulation of flow induced sound for rotating systems. Thereby, the flow is computed by scale resolving simulations using an arbitrary mesh interface scheme for connecting rotating and stationary domains. The acoustic field is modeled by a perturbation ansatz resulting in a convective wave equation based on the acoustic scalar potential and the substational time derivative of the incompressible flow pressure as a source term. We use the Finite-Element (FE) method for solving the convective wave equation and apply a Nitsche type mortaring at the interface between rotating and stationary domains. The whole scheme is applied to the numerical computation of a side channel blower.
Kuehnel, Wolfram, Tautz, Matthias, Becker, Stefan, Kaltenbacher, Manfred, Hüppe, Andreas, Reppenhagen, Aaron
Icing of Ducted Tail Rotor Based on Design of ILX-27 Unmanned HelicopterF-0072-2016-115975/17/2016
The main objective of this paper is to describe the work done in the Polish unmanned helicopter ILX-27 project. The paper presents the effects of icing on the characteristics of helicopter's tail rotor. Simulation of ice accretion process on areas particularly prone to icing and ice formations' influence on operation safety are demonstrated. The influence of ice cover on whole ducted fan device thrust, a force and moment components on the blade are presented. The ice accretion causes mainly an increase of rotor drag.
Gula, Pawel, Neckarz, Piotr, Dziubiński, Adam
Optimization Solutions for Fan Shroud2016-01-13934/5/2016
Fan shroud is one of the critical components in an engine cooling system. It helps in achieving optimum air flow across the heat exchangers. The major challenge is to design a fan shroud which meets noise, vibration and harshness (NVH) requirements without compromising on air flow targets [1]. An improperly designed fan shroud will cause detrimental effects such as undesirable noise and vibration, which will further damage the surrounding components. In current days, multiple simulations and test iterations are carried out in order to optimize its design. The objective of this paper is to provide a design framework to achieve optimized fan shroud that meets NVH requirements in quick turnaround time using Design for Six Sigma (DFSS) approach [2]. The purpose of the Engine cooling system is to maintain the coolant temperature across the vehicle. Fan shroud accommodates the fan which in turn provides necessary air distribution across the radiator in order to have effective engine cooling. In this paper, DFSS approach is adopted to identify and optimize the factors which govern the NVH design of fan shroud. DFSS approach - nominal the best is used for this analysis which has an output, control factors and the noise factors. The modal frequency of the fan shroud is the output from the analysis and is evaluated in two modes, flexible mode and pumping mode. All the design parameters such as wall thickness, number of ribs, structural embossing which affects the output are considered as control factors. The under hood air temperature and the reduction in structural rigidity due to aging are considered as the noise factors. L18 Orthogonal experiment is used for this analysis, 18 design models are created in order to capture different combinations of control factor levels. Multiple control factors are examined to find out which would actually controls the designing of fan shroud in NVH perspective .Structural embossing and number of ribs for fan support are found to be the important design factors which contribute to better shroud NVH characteristics. A CFD simulation is also carried to check the airflow rate of the optimized design. The optimized design suggested in this paper had met both NVH and CFD targets. This study can be used further in order to reduce weight of the shroud and as best practice guidelines for future vehicles fan shroud designing which would ultimately reduce development time and cost.
Konikineni, Prabhakar, Sundaram, V., Sathish, Kumar, Thirukkotti, Sankarasubramanian
Modeling and Analyzing for Hydraulic-Driven Cooling System of Heavy Duty Truck2016-01-02224/5/2016
The heavy duty trucks have large engine power and drive continuously in mountainous area, so the heat dissipation of engine is very important. In the traditional cooling system with fixed transmission ratio fan, the cooling capacity is insufficient and the engine is easy to be over-heated when the engine is working in low speed and heavy load conditions. Owning to the bigger size of electric motor compared to the hydraulic motor, it is not suitably applied to the heavy duty trucks. Contrasted with the electric motor, the hydraulic drive cooling system is widely applied in heavy duty trucks due to smaller size, larger power, continuous speed modulation and flexible installation location. However, the low transmission efficiency of the pump-motor system results in high power consumption of the cooling system. In this paper, the mathematical and simulation model of hydraulic-driven fan cooling system is established for the specific engine. The study applies the digital PID controller of continuous system to control the fan. The control algorithm of anti-integral saturation is compared with the conventional method. The results show that during the time progress of 700s, the mean power consumption with anti-integral algorithm respectively reduce by an average of 40.8%, 35.1% and 29.2% in the target temperature of 363.15K, 364.15K, and 365.15K compared with the traditional control method. Moreover, the PID control with anti-integral algorithm can improve the temperature control accuracy and effectively avoid the excessive cooling.
Zhang, Xingyu, Yang, Bo, Tan, Gangfeng, Mei, Binyu, Li, Zhilei, Yang, Zhongjie, Wang, Can
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