Browse Topic: Compressors

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Resolution of Automotive Air Compressor Noise in Low Powered ICE vehicle2026-26-03141/16/2026
Passenger compartment's interior noise and thermal performance are one of the essential criteria for the driving comfort of vehicles. This paper explains that how the AC compressor noise is optimized in specific to low powered 1 L - ICE engine and 120 cc IVDC compressor combination. This combination is quite challenging due to high operational load & higher operating pressure. For better in-cabin cooling efficiency, compressor operating efficiency to be improved which in turn leads to higher displacement of the compressor. Higher displacement will lead to higher internal forces which leads to more structure borne induced noise in-side the cabin. For this specific combination, the compressor operating pressure reached to 25 bar at most of the driving condition. During dynamic driving condition, compressor metallic tonal noise was reported in one of the A segment vehicle developments. It was reported as very annoying to inside passenger. Transfer Path Analysis, Compressor fixation point
John Britto, Vijay Antony, Maluganahalli-Dharmappa Madhusoodan Sr, 1Lt Madhusoodan, Natarajasundaram, Balasubramanian
Experimental Evidence to Influence Design of Novel Low Lubrication Method for Rotorcraft Secondary Lubrication SystemsF-0081-2025-02795/20/2025
This paper presents experimental research aimed at developing novel low lubrication methods for rotorcraft and jet engines, focusing on sustaining minimal lubrication to prevent catastrophic bearing failure during loss of lubrication (LoL) events or to increase fuel consumption performance on once-through, fuel-oil bearing lubrication engines. Utilizing two high-speed bearing test rigs simulating low and high thrust class engine conditions, the study establishes lower bounds for oil flow rates necessary to maintain thermal stability and prevent thermal runaway in hybrid ball bearings. These findings inform the design of the Zulu Pod (ZPod), a passively driven, self-contained oil delivery system that uses engine compressor bleed air to precisely meter lubricant flow. Engine test stand results demonstrate that replacing traditional fuel-oil lubrication with the ZPod system reduces thrust specific fuel consumption (TSFC) by an average of 7%, with up to 11% savings, without compromising
Boersma, Pieter, Currier, Todd, Ferrante, Jason, Rosenthal, Julius
HVAC NVH Refinement in Electric Vehicle2024-26-02061/16/2024
Customers expect much more advanced features and comfort in electric vehicles. It is challenging for NVH engineers to reduce the vibration levels to a great extent in the vehicle without adding cost and mass. This paper focuses on reducing the tactile vibration in electric vehicle when AC is switched on. Vibration levels were high and modulating in nature in test vehicle. Electric compressor is used for cabin cooling and battery cooling in the vehicle. Compressor is connected to body with the help of isolators. Depending upon cooling load, the compressor operates between 1000 rpm and 8000 rpm. The 1st order vibration of compressor was dominant on tactile locations at all the compressor speeds. Vibration levels were improved by reducing the dynamic stiffness of isolators . To reduce the transfer of compressor vibration further, isolators are provided on HVAC line connection on body and mufflers are provided in suction and discharge line to reduce the effect of pulsation. With the above
S, Nataraja moorthy, Rao, Manchi, Raghavendran, Prasath, Manivannan, Giridharan
Model based Charge control for 3-cylinder TGDI Miller engine containing variable geometry turbocharger2024-26-00431/16/2024
With the increase in the number of automobiles, there is a very strong emphasis on reducing the CO2 pollution which led to evolution of miller cycle engines. However, the inherent characteristic of Miller engine is the lower volumetric efficiency when compared to otto engines because of which small turbo chargers with variable geometry turbines are used to induct air into the engine. With miller engine and VGT turbo charger combination arises the challenges of charge controllability because of lower inertia and reduced vane control area. With conventional turbo charger control methods, the response time is slow thereby leading to turbo lag or sever over boosting, this is overcome by accurate engine modelling and using the same as input for charger control. In this study, model-based calibration approach was performed on a 1.2Litre 3 cylinder Miller GDI engine to model the charge exchange of the engine and use the same for determination required turbine vane positions to achieve the
Veeramani, Vivekanand, Karthi, Ramanathan, Shanmugam Ramakrishnan, Muthu
AC System COP Optimization Through Major or Minor Adjustment of Component Design2022-28-042311/9/2022
In the process of designing of complete cycle of vapour compression refrigerant system, most important part is optimization of performance of all components including compressor, condenser, expansion valve, evaporator and piping and COP of the system . For balancing and COP optimization of air conditioning cycle, it is extremely important that all component selected must be balanced and synchronized with other components relatively. Many researches have been done related to system COP and performance optimization through various method as well as component performance optimization. While optimizing the cycle, changing one component parameter effects the other components behavior and becomes challenge to control all other characteristic. Sometimes even a minor adjustment in the cycle leads change in output result of components which are not preferable. The present paper is about optimization of system COP of refrigerant cycle through various combination of iteration that includes
raj, Abhishek, Bajpai, Himanshu, Agarwal, Roopak, Anal, Rajeev
"Operation Strategies of Heat Pump Systems in High-Performance Electric Vehicles"132999/15/2022
"The energy consumption of a thermal management system cannot be neglected and is a significant contributor compared to the total energy consumption of a battery electric vehicle. Using a heat pump as part of the thermal management system, can heat and reduce energy consumption at low ambient temperatures. A state-of-the-art heat pump system consists of numerous actuators such as fans, pumps, electrical heater, compressor, and valves. An existing challenge remains to develop efficient operational strategies for these components with the corresponding interactions in dynamic boundary conditions. A physical model of the system can be used to optimize the control method and consequently, helps to save energy. The objective of this investigation is to obtain an operating strategy, which efficiently distributes the electric power between the heat pump compressor and the electric heater. In this context, the influence of an optimized, model-based control of the compressor speed on the
Hug, Thimo
Forging a cost-effective way of verifying devices with Analog inputs in UVM based environment2022-26-11815/26/2022
Safety is of utmost importance in the aerospace industry. Hence, verification of SOCs, subsystems and IPs used in the industry should be verified with latest methodology available in the market to deliver an optimal design. Some avionics systems are made up of components with analog inputs such as temperature sensor. These sensors are used in different parts of aircrafts such as Engine Fuel, Cabin temperature control, compressor discharge and many more. Thus, it is very important to verify them thoroughly. This paper talks about a simple technique which generates analog signals and enables such components to be verified in an UVM based verification environment. This can be achieved by creating a small model which generates a debouncing effect. Once the debounced signal is introduced, the devices can be verified thoroughly with the help of UVM testbench. The primary benefit is that the UVM methodology specifies and lays out a set of guidelines to be followed for creation of verification
Harkude, Anand
Effect of Varying Diffuser vane height on CC3 NASA 4:1 Centrifugal Stage Performance2022-26-12105/26/2022
This work is aimed at conducting a computational study to find out the effect of vane less space downstream of the Diffuser vane trailing edge, by varying the height of diffuser vane viz. 50%, 75% and 100% diffuser height, on centrifugal stage performance. The considered centrifugal compressor stage in this study is CC3 NASA 4:1 centrifugal stage. In all the cases diffuser leading edge radius is same. The compressor performance with full diffuser vane configuration (100% diffuser height) is computed and initially compared with test data. The diffuser vane height is then reduced to 50% and 75% of the original length from diffuser leading edge. Hence, the diffuser leading edge location remains same as original 100% diffuser vane height geometry whereas location of trailing edge changes according to vane height. Another part of study is to model 100% diffuser vane height with hub and shroud gaps respectively. The computational study is carried out using CFX v19.1. The paper presents
Kumar, Shailesh, Chougule, Hasham, Abdullah, Qizar, Goswami, Shraman
Development and Application of J3112: A/C Compressor Oil Separator Effectiveness Test Standard2022-01-02183/29/2022
SAE J-Standard J3112 – “A/C Compressor Oil Separator Effectiveness Test Standard” – was developed to provide an analytical means of determining if an a/c compressor with oil separator functionality meets the U.S. EPA criteria of a minimum 50% effectiveness in order to qualify for menu credits for greenhouse gas reduction, per CFR Title 40, §86.1868-12. From the start of the a/c efficiency credit program, OEMs could qualify for menu credit items without providing data on the effectiveness of the product being implemented, but EPA regulations required supporting data from 2020 MY through the end of the current published regulations in 2025 MY. J3112 was developed by the SAE Interior Climate Control MVAC Supplier Committee in order to provide a standardized procedure for determining oil separator effectiveness in order to comply with the EPA requirements for 2020-2025 model years. This presentation will provide background on how J3112 was developed, and how it is used in order to provide
Taylor, Dwayne
Alternate Methodology for Air Conditioning Compressor Capacity Measurement2021-28-01419/15/2021
The actual compressor capacity is generally different from the theoretical capacity due to internal leakages and manufacturing imperfections. Conventionally, compressor volumetric efficiency is measured using system level testing consisting of evaporator, condensor & TXV in a closed loop system with known refrigerants. In this paper a methodology is demonstrated for evaluating any auto mobile air conditioning compressors' volumetric efficiency & capacity by using atmospheric air in an open loop system. Wide range of compressors (~70cc to ~220 cc) were tested and data generated. The process parameters of the test rig was continuously monitored until stabilization and readings were taken. It is observed that the results are comparable with closed loop performance results. Comparative study is presented for tested volumetric capacity and theoretically calculated value along with variations. Henceforth, the outlined approach gives deeper insight into design effectiveness, any imperfections
Yadav, Aditya Pratap, Goel, Arun Kumar, Sharma, Kamal
Study of various techniques for the reduction of Mobile Air Conditioning (MAC) compressors noise inside the passenger cabin2021-28-01269/15/2021
Due to stiff competition among the Original Equipment Manufacturer (OEM's), the Comfort, Fuel efficiency & Safety are the key factors that drives the vehicle business. The main factors of vehicle comfort are vibration, noise, thermal comfort (temperature), air quality, light and ergonomics. In this context Compressor Noise plays an important role in the comfort of the passengers. Therefore, it's a big challenge for the automotive engineer to find the source of noise and reduce the same during the development. The objective of this paper to understand the various compressors noise characteristic during static (i.e initial engagement of compressor) and dynamic condition (i.e during compressor running). Key words: Comfort, Compressor noise, NVH
Anandan, Ram, Venkateshwararao, Manchi, Patel, Yash
Continuously Variable Displacement Drive for Engines Part 2, Design, Analysis, and Test2021-01-04514/6/2021
A new type of drive system has been designed, analyzed, patented, prototyped, and tested. The drive’s unique capabilities include the ability to vary the bottom dead center position to reduce the stroke, and simultaneously vary the top dead center position to achieve the desired compression ratio with one simple, low friction mechanism. The purpose of the concept is to reduce losses associated with operation at partial load as most engines spend a preponderance of their operating life at partial load. This paper covers the design and analysis, prototyping, and testing of the unit as an air compressor. Engine simulation of the unit configured as a gasoline engine showed a ~30% improvement in fuel economy on a 10-mode weighted cycle and is covered in SAE 2021-01-0442, “Continuously Variable Displacement Drive for Engines Part 1, Performance Simulation.”
Arnold, Steve, Riesland, Dave
Method for Evaluating the Flow Properties of Pumpable SealersJ2025_202101 (Current)1/7/2021
This SAE Recommended Practice sets forth a method for evaluating the flow properties of automotive sealers that have been dispensed via a high pressure automatic system.
Materials, Processes and Parts Council
Safety and Design Standards for Motor Vehicle Refrigerant Vapor Compression SystemsJ639_202011 (Current)11/9/2020
This SAE Standard applies to refrigerant vapor compression systems that provide cooling and/or heating for passenger cars, light trucks, and commercial vehicles (on and off road) that use automotive type mobile air conditioning (MAC) systems. Large trucks, buses, and other vehicles that do not use typical automotive A/C systems or use refrigerants not listed in this document are not covered by this standard. This standard covers vehicles with MAC systems using belt driven compressors and electric motor driven compressors. This document provides industry-recognized standards for the design, assembly, and test of MAC systems, including necessary service equipment, and is intended to cover all phases of the lifetime of MAC systems to minimize environmental, health, and safety impacts. The standards listed in this document cover the currently accepted industry guidelines and procedures. The standards can be used as requirements for regulatory authorities to meet minimum environmental
Interior Climate Control Vehicle OEM Committee
Safety and Design Standards for Motor Vehicle Refrigerant Vapor Compression SystemsJ639_202011-TEST-REC (Historical)11/9/2020
This SAE Standard applies to refrigerant vapor compression systems that provide cooling and/or heating for passenger cars, light trucks, and commercial vehicles (on and off road) that use automotive type mobile air conditioning (MAC) systems. Large trucks, buses, and other vehicles that do not use typical automotive A/C systems or use refrigerants not listed in this document are not covered by this standard. This standard covers vehicles with MAC systems using belt driven compressors and electric motor driven compressors. This document provides industry-recognized standards for the design, assembly, and test of MAC systems, including necessary service equipment, and is intended to cover all phases of the lifetime of MAC systems to minimize environmental, health, and safety impacts. The standards listed in this document cover the currently accepted industry guidelines and procedures. The standards can be used as requirements for regulatory authorities to meet minimum environmental
Interior Climate Control Vehicle OEM Committee
New High-Flow Valve for Portable Oxygen Concentrator SystemsTBMG-372487/1/2020
Battery-powered, highly portable oxygen concentrators are a growing trend in patient mobility, enabling more and more oxygen-dependent patients to leave behind bulky home oxygen concentrator systems; larger, older “portable” concentrators; or oxygen tanks for hours at a time. But creating and building devices with high oxygen capacity in a size and weight easily managed by an oxygen-dependent individual remains a major engineering challenge.
Methodology to quantify the undesirable effects of the localized inefficiency of heat pick-up in suction line on an automotive air-conditioning system2020-28-00364/30/2020
The automotive application places very special demands on the air conditioning system. As is the case with any other process, system efficiency is very important and the automotive air-conditioning application is no exception. While the characteristics of all the major components in the air conditioning system like compressor, condenser, evaporator and blower contribute to overall system efficiency, localized inefficiencies do play a part and so must be kept to a minimum, especially in this day and age when extra emphasis is being paid on sustainability. One such phenomenon that contributes to the system inefficiency is heat pick-up in suction line. Since the temperature at the evaporator-outlet is quite lower than ambient and also its surroundings (steering system pipes and hoses, engine, air intake pipes and so on), the refrigerant picks up heat as it moves along the suction line up to the compressor inlet. This heat pick-up is detrimental to the overall system performance. Even
Dubey, Mayank Manoj, Tadigadapa, Suresh, Ghorpade, Santosh, Shukla, Ankit, Reddy, Y.S.Sarath
Energy Recovery Rate from an Electric Air-Cycle System under the Cruising Altitude and Speed2019-01-19059/16/2019
A new electric air-cycle system of aircrafts is investigated focusing on energy recovery from the exhaust air. The working fluid of air has the higher energy level in the cabin than in the outside during the cruise because the outside air is at low pressure and low temperature. In the system, by setting a recovery turbine behind the cabin, the discharged energy can be collected, although the working fluid through the system has been only discharged from the cabin into the outside. We perform a thermodynamic cycle-analysis, where the temperature, pressure, entropy, etc. are calculated at each position of the cycle by considering the two pressure ratios of the compressors as variable parameters to show T-s diagram. In addition, we obtain an energy recovery rate of the recovery energy to the necessary power for the electric compressor. The energy recovery rate is roughly estimated 40-80% under the reasonable practical operating conditions.
Adachi, Takahiro, Seki, Naoki, Oyori, Hitoshi, Muraoka, Mikio
Experimental Study and Analysis of Ice Crystal Accretion on a Gas Turbine Compressor Stator Vane2019-01-19276/10/2019
A significant number of historical engine powerloss events have recently been attributed to ingestion of high altitude ice crystals, prompting regulators to expand engine certification envelopes to incorporate ‘ice crystal icing’ conditions. There has been a resulting effort by OEMs and academia to develop analytical and semi-empirical models for the phenomenon, partly through use of rig testing. The current study presents results and analysis of experiments conducted in the National Research Council’s Research Altitude Test Facility (RATFac). The experiments used a simplified compressor stator vane test article, designed to produce data to build semi-empirical models and validate an existing ice crystal icing code. Accretion growth rates, extracted from backlit shadowgraphy, are presented as a function of test condition, and the algorithm of a new image processing technique using Canny filtering is discussed. Wet bulb temperature, Mach number, particle size and test article angle of
Bucknell, Alexander, McGilvray, Matthew, Gillespie, David, Parker, Liam, Forsyth, Peter, Saad Ifti, Hassan, Jones, Geoffrey, Collier, Benjamin, Reed, Alasdair
Microwave Technique for Liquid Water Detection in Icing Applications2019-01-19306/10/2019
The partial melting of ingested ice crystals can lead to ice accretion in aircraft compressors, but accurately measuring the relatively small fraction of liquid water content in such flows is challenging. Probe-based methods for detecting liquid water content are not suitable for deployment within turbofan engines, and thus alternatives are sought. Recent research has described approaches based on passive microwave sensing. We present here an approach based on active microwave transmission and reflection, employing a vector network analyzer. Utilization of both transmission and reflection provides additional data over and above emission or transmission only, and permits a more controllable environment than passive sensing approaches. The paper specifically addresses the question of whether such an approach is viable within the context of representative icing wind tunnel and engine flow conditions. A quasi-thermal equilibrium approach is presented herein to estimate the melting ratio
Leis, John, Buttsworth, David, Saeed, Ramiz, Saleh, Khalid, McGilvray, Matthew, Gillespie, David
Two-Way Flow Coupling in Ice Crystal Icing Simulation2019-01-19666/10/2019
Numerous turbofan power-loss events have occurred in high altitude locations in the presence of ice crystals. It is theorized that ice crystals enter the engine core, partially melt in the compressor and then accrete onto stator blade surfaces. This may lead to engine rollback, or shed induced blade damage, surge and/or flameout. The first generation of ice crystal icing predictive models use a single flow field where there is no accretion to calculate particle trajectories and accretion growth rates. Recent work completed at the University of Oxford has created an algorithm to automatically detect the edge of accretion from experimental video data. Using these accretion profiles, numerical simulations were carried out at discrete points in time using a manual meshing process. That work showed that flow field changes caused by a changing accretion profile had significant effects on the collection efficiency of impinging particles, ultimately affecting the mass of accreted ice and its
Connolly, Jonathan Paul, McGilvray, Matthew, Gillespie, David, Bucknell, Alex, Parker, Liam, Jones, Geoffrey, Collier, Benjamin
Validation and Instrumentation of a Small Modular Multi-Stage Axial Compressor for Ice Crystal Icing Research2019-01-19406/10/2019
The National Research Council of Canada (NRC) has undergone the development of a Small Axial Compressor Rig for modelling altitude ice accretion in aircraft engines. The rig consists of two axial compressor stages measuring approximately 150mm in diameter, an extension duct to allow residence time for partial melting of ice crystals and a test piece. The axial compressor stages are intended to provide realistic engine conditioning such as fracture, pressure rise, temperature rise and centrifuging of glaciated ice crystals entering the rig. The rig was designed for use in altitude icing wind tunnels such as the NRC’s altitude icing wind tunnel (AIWT), research altitude test facility (RATFac.), and those of other organization such as NASA Glenn and Technical University of Braunshweig. Previous development work [1] provided partial validation of the aerodynamic performance of just the first compressor stage at 90% power. Recent development work has concluded the aerodynamic validation of
Neuteboom, Martin, Chalmers, Jennifer, Currie, Thomas
Surge Prediction in a Single Sequential Turbocharger (SST) Compressor Using Computational Fluid Dynamics2019-01-14906/5/2019
The Single Sequential Turbocharger (SST) used in Ford’s 6.7L Scorpion Diesel is analyzed using Computational Fluid Dynamics (CFD) to draw conclusions about the compressor stability at low mass flows. The SST compressor concept consists of a double-sided wheel which flows in parallel fed by two separate inlets (front and rear), followed by a single vane-less diffuser, and a volute. CFD simulations for the full stage are performed at low mass flow rates Both, front and rear, sides have ported shroud casing-treatment (CT) in the inlet region. An objective of the analysis is to determine which side of the SST unit compressor (front or rear on the double-sided wheel) suffers flow break down first as the mass flow is reduced, and its impact on the overall stability of the SST compressor. Another objective is to better understand the interactions between the compressor inlet flow and the flow through the casing-treatment. It has been observed that these interactions reduce the effectiveness
Karim, Ahsanul, Wade, Robert, Morelli, Anthony, Miazgowicz, Keith, Lizotte, Brian
Prediction of Broadband Noise in an Automotive Centrifugal Compressor with Three-Dimensional Computational Fluid Dynamics Detached Eddy Simulations2019-01-14876/5/2019
Centrifugal compressors for automotive turbochargers must operate over wide speed and flow ranges to provide the required air pressure and mass flow rate to the intake manifold of the internal combustion engines. At a fixed rotational speed, the flow field near the inducer of the impeller becomes increasingly unstable with decreasing flow rate, as the incidence angle grows between the air flow approaching the impeller, relative to the tangent of the main impeller blades at the leading edge. Flow field measurements conducted earlier have revealed that once the incidence angle exceeds a critical value (nearly independent of rotational speed) of approximately 15°, reversed flow near the periphery (blade tips) starts penetrating upstream of the impeller, with a high tangential velocity in the direction of impeller rotation. As the incidence angle is increased towards this critical value, whoosh noise elevates, where it remains high for a significant portion of the mid-flow operating range
Dehner, Rick, Selamet, Ahmet
Swept Volume Approach for the Characterization of Pumping Loss of Shrouded Meshed Cylindrical GearsF-0075-2019-146815/13/2019
High speed rotorcraft transmissions are subject to load-independent power losses consisting of drag and pumping loss. Tightly conforming shrouds enclosing the transmission gears are often incorporated to reduce the drag component of the total load independent losses. However, tightly conforming axial shrouding can result in an increase in the pumping loss component. Quantifying the pumping loss of shrouded gear transmissions has been the subject of many studies. This study presents a new approach for estimating pumping loss based on the concept of swept volume borrowed from the positive displacement pump and compressor industry. In this study, pumping loss of shrouded gear transmissions is considered to be related to the swept volume of the gear sets and the downstream flow resistance created by the shroud clearances. The drag loss and pumping loss of a spur gear pair have been determined through testing using the NASA Glenn Research Center Gear Windage Test Facility. The results from
Hurrell, Michael, Delgado, Irebert
Development of a Climate and Altitude Simulation Test Bench for Handheld Power Tools2018-32-003310/30/2018
A climate and altitude conditioning test bench was developed at the Institute of Energy Efficient Mobility (IEEM) of Karlsruhe University of Applied Sciences to evaluate the overall sustainability of using innovative biofuels in handheld power tools such as chainsaws, trimmers and blowers under any typical operating condition worldwide. The 6 m3 hermetically sealed and thermally insulated test chamber is large enough to fit the entire power tool. A two-stage refrigeration system with intake air drying and electric heating allows for realistic temperature conditions to be set in the test chamber, ranging from arctic cold to tropical heat (-28 to 45 °C). Altitudes of up to 3500 m above sea level can be simulated using a throttle valve at the inlet of the chamber and a pressure-controlled rotary screw compressor positioned downstream the test chamber outlet. The air-cooled engines to be tested are fully exposed to the ambient conditions inside the test chamber, are able to aspirate the
Martel, Artur, Scholl, Fino, Weierter, Dennis, Kettner, Maurice
Potential Improvements in Turbofan’s Performance by Electric Power Transfer2018-01-196210/30/2018
Bleeding in engines is essential to mitigate the unmatched air massflow between low and High Pressure (HP) compressors at low speed settings, thus avoiding unstable operation due to surge and phenomena. However, by emerging the More Electric Aircraft (MEA) the engine is equipped with electrical machines on both high and Low Pressure (LP) spools which enables transfer of power electrically from one spool to another and hence provides the opportunity to operate engine core components closer to their optimum design point at off-design conditions. At lower power setting of the engine, HPC speed can be increased by taking power from LP shaft and feeding it to HP shaft which can lead to the removal of the bleeding system which in turn reduces weight and fuel consumption and help to overcome engine instability issues. Fuel consumption can be decreased by decreasing inconsistent thrust with the aircraft mission for flight and ground idle settings. This paper investigates the idea of power
Balaghi Enalou, Hossein, Le-Peuvedic, Jean-Marc, Rashed, Mohamed, Bozhko, Serhiy
Popcorn-Driven Robotic ActuatorsTBMG-3307910/1/2018
When heated, popcorn can expand more than 10 times in size, change its viscosity by a factor of 10, and transition from regular to highly irregular granules with surprising force. These unique qualities can power inexpensive robotic devices that grip, expand, or change rigidity.
Effective Suppression of Surge Instabilities in Turbocharger Compression Systems through a Close-Coupled Compressor Inlet Restriction2018-01-17149/10/2018
The current work demonstrates effective suppression of compression system surge instabilities by installing a variable cross-sectional flow area restriction within the inlet duct of a turbocharger centrifugal compressor operating on a bench-top facility. This restriction couples with the compressor, similar to stages in a multi-stage turbomachine, where the effective pressure ratio is the product of those for the restriction and compressor. During experiments at constant compressor rotational speed, the compressor is stable over the negatively sloped portion of the pressure ratio vs. flow rate characteristics, so the restriction is eliminated within this operating region to preserve compressor performance. At low flow rates, the slope of the compressor alone characteristics reaches a positive value, and the unrestricted compression system enters mild surge. Further reduction of flow rate with the unrestricted compressor inlet results in a sudden transition to deep surge instabilities
Dehner, Rick, Selamet, Ahmet, Miazgowicz, Keith
Limits and Fits - International Metric Tolerance SystemAIR1758A (Current)8/9/2018
This information report provides guidance when the ISO International metric tolerance system for limits and fits per ISO/R286 or ANSI B4.2-1978 is applied on a standard, and also provides a selected series of limits and fits for powerplant construction suitable for holes and shafts up to 500 mm. For holes or shafts over 500 mm or for limits and fits not shown, ISO/R286 should be consulted.
E-25 General Standards for Aerospace and Propulsion Systems
Multi-Axis Voxel-Based CNC Machining of Centrifugal Compressor AssembliesF-0074-2018-127985/14/2018
ABSTRACT The use of computer-aided manufacturing (CAM) software is essential in the rapid production of high-quality computer numerical control (CNC) machining toolpaths for complex parts. Typical CAM software relies on analytical representations of part geometry, where curves and surfaces are described by parametric functions. This paper proposes the use of a novel way to represent part geometry known as a voxel model. A voxel model uses a three-dimensional array of small cubes to represent a part volume; these cubes, or voxels, are the three-dimensional analog of two-dimensional pixels in an image. The use of voxels for a CAM application enables higher surface complexity, simplified collision checking, and more robust analysis of material removal than would be possible with typical parametric CAM. The unique capabilities of the voxel-based CAM approach described in this paper enable rapid production of high-quality 5-axis toolpaths for machining complex parts, such as the centrifugal
Kurfess, Thomas, Tucker, Tommy, Silberglied, Chelsea, Lynn, Roby, Saleeby, Kyle, Saldana, Christopher
Experimental Investigation on Surge Phenomena in an Automotive Turbocharger Compressor2018-01-09764/3/2018
Downsizing and turbocharging are today considered an effective way to reduce CO2 emissions in automotive gasoline engines, especially for the European and US markets. In the broad field of research and development for engine boosting systems, the instability phenomenon of surge has gathered considerable interest in recent years, as the main limiting factor to high performance boosting and boost pressure control. To this extent, developing an in-depth knowledge of the surge dynamics and on the phenomena governing the transition from stable to unstable operation can provide very valuable information for the design of the intake system and boost pressure control algorithms, allowing optimal boost pressure without compromising the transient response. This paper describes an experimental study that aims at better understanding the phenomena leading to the inception of surge, and exploring the effects of the downstream circuit geometry on the compressor dynamic behavior in surge and prior to
Marelli, Silvia, Misley, Anna, Silviestri, Paolo, Capobianco, Massimo, Taylor, Alexandra, Canova, Marcello
Numerical Simulation of Oil Separator of an Automotive Swash Type Compressor2018-01-04884/3/2018
In the present study a numerical investigation is performed by using computational fluid dynamics (CFD) aiming to figure out and maximize the separation efficiency of an oil separator by changing the various design parameters. A typical automotive swash plate type compressor is chosen for this numerical investigation. Basically oil separation becomes very important where oil return is quite problematic due to the multiple constraints in piping layout design. Efficient oil separation makes the compressor lubrication easy and prevents from seizing during running. It also enhances the heat transfer from heat exchanger by reducing or separating oil from the refrigerant flowing in the air conditioning (AC) circuit. A computational method is proposed to analyze an oil separator fitted in a swash plate compressor. Eulerian multiphase model is employed to simulate the oil and refrigerant mixture model. Separation efficiency is predicted numerically by changing the nozzle diameter, separator
Sen, Somnath
Oil Circulation Rate in Ejector Cooling Cycles2018-01-00774/3/2018
In this study, the influence of compressor speed, ejector motive nozzle needle position and evaporator inlet metering valve opening on the oil circulation rates (OCRs) of an automotive R744 transcritical standard ejector cycle was experimentally investigated. Significantly higher OCR (~10%) was observed at the evaporator inlet of the ejector cycle than at the high pressure side. It has been observed that evaporator OCR was increased with increasing compressor speed. When the motive nozzle needle moved towards the nozzle throat, both compressor discharge flow rate and evaporator OCR were observed to be significantly lowered. As the evaporator inlet metering valve opening was adjusted, the compressor mass flow rate did not vary significantly while the evaporator mass flow rate decreased with decreasing metering valve opening. The evaporator OCR decreased from 6.5% to 2.2% as the metering valve opening varied from 86% to 27%.
Zhu, Jingwei, Botticella, Francesco, Elbel, Stefan
Optimization of the Engine Intake Air Temperature through the Air Conditioning Unit2018-01-09734/3/2018
In modern turbocharged internal combustion engines the cooling of the air after the compression stage is the standard technique to reduce temperature of the engine intake air aimed at improving cylinder filling (volumetric efficiency) and, therefore, overall global efficiency. At present, standard values for the intake air temperature are in the range 30-70°C, dependently on engine load, external air conditions and vehicle speed and the adoption of a dedicated cooling fluid operating at low temperatures (-10-0°C) is addressed as the most viable option to achieve an effective temperature reduction. This paper investigates a pilot engine set-up, featuring an evaporator on the intake line of a turbocharged diesel engine, tested on a high speed dynamometer bench: the evaporator was a part of an air refrigeration unit – the same used for cabin cooling - composed also by a compressor, a condenser and a thermostatic expansion valve. The effects of the undercooling of the charge air have been
Di Battista, Davide, Vittorini, Diego, Di Bartolomeo, Marco, Cipollone, Roberto
Performance Characteristics of a Mobile Heat Pump System at Low Ambient Temperature2018-01-00764/3/2018
The demand for mobile heat pump systems increases with the growing popularity of electric vehicles. One big challenge of such systems using low pressure refrigerant is the substantial drop of heating capacity at low ambient temperature conditions, when heat is most needed. The low suction density associated with low operating pressure in the evaporator is the major reason for the capacity drop. In extremely low ambient temperature, compressor speed may need to be regulated in order to prevent suction pressure going below atmospheric pressure, hence further reducing heat pumping capability. Other factors like pressure drop induced temperature glide and refrigerant maldistribution in the outdoor evaporator also weakens the system ability to absorb heat from ambient air. This paper presents detailed and in-depth analysis of the performance and limiting factors on low ambient temperature operation of a mobile heat pump system using refrigerant R1234yf. Experimental data are taken for
Feng, Lili, Hrnjak, Predrag
Equation-Based Compressor and Turbine Modeling for Variable Geometry Turbochargers2018-01-09664/3/2018
As modern engines are being downsized, turbochargers are becoming increasingly common. The operation of turbochargers is usually captured by a map provided by the manufacturer. However, the complexity of these maps makes them difficult to use for turbocharger estimation and control strategies. This work focuses on a method that is able to reduce the compressor and turbine maps from a cloud of points into a set of equations. This is accomplished by defining a series of non-dimensional and normalized variables that define a plane transformation. In this new plane, all the points of the map converge approximately into a line and the equation for this line can be found using a least square regression. While this strategy has been used previously, this work includes additional variables as well as an optimization process, which proved to be better at replicating the original maps than existing methods. The new technique is shown to accurately replicate the data contained in the maps and
Pulpeiro Gonzalez, Jorge, Hall, Carrie
Performance Optimization of Compressor Rotor Clutch Sub-assembly Using Electro- Magnetic Analysis2018-01-04844/3/2018
Rotor Clutch sub-assembly is one of the very important sub-assemblies (S/A) of an automotive compressor as it delivers the required torque/power to run the compressor. It mainly consists of rotor and bearing, stator, hub and armature. Rotor is rotated by engine pulley through belt drive system, while stator housing has got number of coils winded around stator slot. The hub sub-assembly is attached to the compressor shaft via spline arrangement and bolted across. When direct current (DC) is supplied to the terminal of the rotor, an electromagnetic field is generated which causes to attract the hub part towards rotor. Once the hub and rotor gets engaged each other, torque is transmitted to the compressor shaft which then helps to complete the suction and compression of refrigerant gas and thus making the vapor cycle run to produce adequate cooling in the air-conditioning (AC) system. Hence it is most important to ensure adequate and even distribution of electromagnetic field which is
Meena, Avadhesh, Sen, Somnath
Flow Visualization and Experimental Measurement of Compressor Oil Separator2018-01-00674/3/2018
This article presents basic separation mechanisms with coalescing/impinging separators studied as the add-on to current popular centrifugal designs. The coalescence and impingement of oil on wire mesh and wave-plates are visualized and tested to investigate the impact of geometry and flow conditions on oil separation efficiency. Re-entrainment phenomenon is explained based on the mass balance. Oil mist flow at the swashplate reciprocating compressor discharge is quantified by video processing method to provide detailed information of the oil droplets. The physics behind oil separator is illustrated by visualization and measurement in this study, which gives useful guidelines for oil separator design and operation. The flow visualization shows the details of oil passing through different oil separation structures. Videos are quantified to provide information like droplet size distribution and liquid volume fraction. Experimental measurement shows that effective separation efficiency
Xu, Jiu, Hrnjak, Pega
Air Dryer Installation ProcedureJ2383_201711 (Historical)11/15/2017
This SAE Recommended Practice establishes uniform Installation Parameters for desiccant Air Dryers for vehicles with compressed air systems.
Truck and Bus Brake Supply and Control Components Committee
A Comparison of On-Engine Surge Detection Algorithms using Knock Accelerometers2017-01-242010/8/2017
On-engine surge detection could help in reducing the safety margin towards surge, thus allowing higher boost pressures and ultimately low-end torque. In this paper, experimental data from a truck turbocharger compressor mounted on the engine is investigated. A short period of compressor surge is provoked through a sudden, large drop in engine load. The compressor housing is equipped with knock accelerometers. Different signal treatments are evaluated for their suitability with respect to on-engine surge detection: the signal root mean square, the power spectral density in the surge frequency band, the recently proposed Hurst exponent, and a closely related concept optimized to detect changes in the underlying scaling behavior of the signal. For validation purposes, a judgement by the test cell operator by visual observation of the air filter vibrations and audible noises, as well as inlet temperature increase, are also used to diagnose surge. The four signal treatments are compared
Kerres, Bertrand, Cronhjort, Andreas, Mihaescu, Mihai, Stenlaas, Ola
Study on Nonlinear Rotordynamics Characteristics for Electric Compound Turbocharger2017-01-241810/8/2017
The electric compound turbocharger(ECT) which integrates a high speed motor into a turbocharger rotor shaft can be used transiently to accelerate the turbocharger more quickly in response to an acceleration requirement. It can utilize the exhaust gas energy fully to improve the engine fuel efficiency and benefit for engine with lower emissions. The key technique of ECT is to solve the reliability problems when an electrical motor is integrated into a turbocharger shaft between the turbine and compressor wheels will increase the burden for the bearing support and affect the turbocharger shaft rotation characteristics. In order to know the dynamics behavior of higher load bearing system is explored for reliability, this paper focus on the nonlinear rotor dynamics characteristics of ECT rotor bearing system. Based on the principle and structure of ECT rotor bearing system, the basic theory method and dynamics model of rotor bearing system is established considered the nonlinear fluid film
Zhang, Hong, Wang, Zhuo, Hong, Zhouzhensen
The Effect of Ported Shroud Recirculating Casing Treatment on Turbocharger Centrifugal Compressor Acoustics2017-01-17966/5/2017
Ported shroud compressor covers recirculate low momentum air near the inducer blade tips, and the use of these devices has traditionally been confined to extending the low-flow operating region at elevated rotational speeds for compressors on compression-ignition (CI) engines. Implementation of ported shrouds on compressors for spark-ignition (SI) engines has been generally avoided due to operation at pressure ratios below the region where ported shrouds improve low-flow range, the slight efficiency penalty, and the perception of increased noise. The present study provides an experimental investigation of performance and acoustics for a SI engine turbocharger compressor both with a ported shroud and without (baseline). The objective of implementing the ported shroud was to reduce mid-flow range broadband whoosh noise of the baseline compressor over 4-12 kHz. At the compressor inlet, elevated BPF noise of the ported shroud partially offset the mid-flow range (4-12 kHz) whoosh noise
Dehner, Rick D., Selamet, Ahmet, Steiger, Michael, Miazgowicz, Keith, Karim, Ahsanul
Vibration Fatigue for Chassis-Mounted, Cantilevered Components2017-01-03603/28/2017
Vehicle chassis mounted cantilevered components should meet two critical design targets: 1) NVH criterion to avoid resonance with road noise and engine vibration and 2) satisfied durability performance to avoid any incident in structure failure and dysfunction. Generally, two types of testing are performed to validate chassis mounted cantilevered component in the design process: shaker table testing and vehicle proving ground testing. Shaker table testing is a powered vibration endurance test performed with load input summarized from real proving ground data and accurate enough to replicate the physical test. The proving ground test is typically performed at critical milestones with full vehicles. Most tests are simplified lab testing to save cost and effort. CAE procedures that virtually replicate these lab tests is even more helpful in the design verification stages. A method for defining load input, Power Spectral Density or Sine Sweep, to predict the fatigue life of chassis
Song, Guangtian Gavin, Peters, Joe, Hopson, Steven, Jordan, Adrian
R744 Parallel Compression Cycle for Automotive Climate Control2017-01-01753/28/2017
The natural refrigerant, R744 (CO2), remains a viable solution to replace the high GWP refrigerant R134a which is to be phased out in light-duty vehicles in EU and US market. In this study, thermodynamic analysis is performed on a R744 parallel compression system to evaluate its potential in automotive climate control. The model adopts a correlation of isentropic efficiency as a function of compression ratio based on a prototype R744 MAC compressor and accounts for the operating limits defined in the latest DIN specifications. Optimization is run over typical MAC operating conditions which covers both transcritical and subcritical domain. Comparing to the conventional single compression cycle, effectiveness of parallel compression is found most pronounced in low evaporating temperature and high ambient conditions, with up to 21% increase in COP and 5.3 bar reduction in discharge pressure observed over the considered parametric range. Correlations of the optimal discharge pressure and
He, Jing, Johnston, Bill, Dhar, Debasish, Lohmeyer, Loren
Turbo Speed Estimation Using Fixed-Point Iteration2017-01-05913/28/2017
1 In modern turbocharged engines the power output is strongly connected to the turbocharger speed, through the flow characteristics of the turbocharger. Turbo speed is therefore an important state for the engine operation, but it is usually not measured or controlled directly. Still the control system must ensure that the turbo speed does not exceed its maximum allowed value to prevent damaging the turbocharger. Having access to a turbo speed signal, preferably by a cheap and reliable estimation instead of a sensor, could be beneficial for over speed protection and supervision of the turbocharger. This paper proposes a turbo speed observer that only utilizes the conditions around the compressor and a model for the compressor map. These conditions are either measured or can be more easily estimated from available sensors compared the conditions on the turbine side. The observer utilizes an ellipse model for the compressor that outputs pressure ratio as a function of turbo speed and
Thomasson, Andreas, Llamas, Xavier, Eriksson, Lars
Development of the Large Type Electric-Driven Refrigerator for the HV Truck2017-01-01373/28/2017
In respect to the present large refrigerator trucks, sub-engine type is the main product, but the basic structure does not change greatly since the introduction for around 50 years. A sub-engine type uses an industrial engine to drive the compressor, and the environmental correspondence such as the fuel consumption, the emission is late remarkably. In addition, most of trucks carry the truck equipment including the refrigerator which consumes fuel about 20% of whole vehicle. Focusing on this point, the following are the reports about the system development plan for fuel consumption reduction of the large size refrigerator truck. New concept is to utilize electrical power from HV system to power the electric-driven refrigerator. We have developed a fully electric-driven refrigerator system, which uses regenerated energy that is dedicated for our refrigerator system. It is the world’s first new concept to use the all electricity that regenerated by HV system for the drive of our electric
Ando, Akira, Hamashima, Koichi, Kato, Shinji, Tomita, Noriyuki, Uejima, Takahiro
Automotive A/C Servicing – Refrigerant Flushing of a Failed A/C System2017-01-01673/28/2017
The failure of an A/C system often results in the introduction of contaminants to the A/C system. The sources of the contaminants include debris from damaged components and debris from the surrounding environment. Returning the A/C system to service requires the removal of these contaminants from any reused components. The recommended approach to cleaning contaminated components and systems is to flush with a solvent flushing machine. Previous internal studies have concluded that solvent flushing will remove all contaminants, restoring component and system performance. Many commercial refrigerant recovery and recharge machines include a refrigerant “flush” feature which can flush oil from the system and components with the systems refrigerant. The effectiveness of using the “flush” feature of a refrigerant recovery and recharge machine with an added in-line filter to remove contaminants is investigated. One gram of Arizona Test Dust is introduced to the suction line of an automotive A
Lambert, Steven, Jamo, William, Kurtz, Mike
Automated Calibration for Compressor Recirculation Valve Control2017-01-05943/28/2017
Turbocharger compressors are susceptible to surge – the instability phenomena that impose limitations on the operation of turbocharged engines because of undesired noise, engine torque capability constraints, and hardware strain. Turbocharged engines are typically equipped with a binary compressor recirculation valve (CRV) whose primary function is to prevent compressor surge. Calibration of the associated control strategy requires in-vehicle tests and usually employs subjective criteria. This work aims to reduce the calibration effort for the strategy by developing a test procedure and data processing algorithms. An automated calibration for CRV control is developed that will generate a baseline calibration that avoids surge events. The effort to obtain the baseline calibration, which can be further fine-tuned, is thereby significantly reduced. Procedures are developed for testing and analysis that combines a previously developed surge characterization method with unconstrained
Xiao, Baitao, Hellstrom, Erik, Wang, Yan, Buckland, Julia, Santillo, Mario
Thermodynamic Potential of Electrical Turbocharging for the Case of Small Passenger Car ICE under Steady Operation2017-01-05263/28/2017
The proposed paper deals with thermodynamic optimization of highly flexible ICE (variable compression ratio, intake/exhaust VVA) while comparing e-turbocharging concept with classical one. The e-turbocharging approach is based on idea that compressor/turbine has its own electric machine (motor/generator) and that additional electric energy can be supplied/attached from/to engine crank train. Hence it allows independent control of compressor/turbine. On the other hand, classical approach is based on a standard mechanical connection between turbine and compressor. The whole system (flexible engine + boost device) is optimized under steady operation – low load (BMEP of 4 bar), medium load (BMEP of 13 bar), high load (BMEP of 30, 25 and 18 bar) and maximum load are considered. Moreover, 3 combustion concepts are considered – classical SI and CI, and ideal RCCI. Sensitivity study of selected parameters is performed: e.g., efficiency of electric machine(s), HP exhaust manifold volume. All
Vitek, Oldrich, Macek, Jan
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