Browse Topic: Compressors

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AC System COP Optimization Through Major or Minor Adjustment of Component Design2022-28-042311/09/2022
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"1329909/15/2022
"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 environment2022-26-118105/26/2022
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 Performance2022-26-121005/26/2022
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 Standard2022-01-021803/29/2022
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 Measurement2021-28-014109/15/2021
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 cabin2021-28-012609/15/2021
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 Test2021-01-045104/06/2021
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)01/07/2021
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)11/09/2020
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)11/09/2020
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
Methodology to quantify the undesirable effects of the localized inefficiency of heat pick-up in suction line on an automotive air-conditioning system2020-28-003604/30/2020
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 Speed2019-01-190509/16/2019
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 Vane2019-01-192706/10/2019
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
Two-Way Flow Coupling in Ice Crystal Icing Simulation2019-01-196606/10/2019
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 Research2019-01-194006/10/2019
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
Microwave Technique for Liquid Water Detection in Icing Applications2019-01-193006/10/2019
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
Prediction of Broadband Noise in an Automotive Centrifugal Compressor with Three-Dimensional Computational Fluid Dynamics Detached Eddy Simulations2019-01-148706/05/2019
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
Surge Prediction in a Single Sequential Turbocharger (SST) Compressor Using Computational Fluid Dynamics2019-01-149006/05/2019
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
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
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
Effective Suppression of Surge Instabilities in Turbocharger Compression Systems through a Close-Coupled Compressor Inlet Restriction2018-01-171409/10/2018
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)08/09/2018
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
Flow Visualization and Experimental Measurement of Compressor Oil Separator2018-01-006704/03/2018
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
Experimental Investigation on Surge Phenomena in an Automotive Turbocharger Compressor2018-01-097604/03/2018
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
Oil Circulation Rate in Ejector Cooling Cycles2018-01-007704/03/2018
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
Performance Characteristics of a Mobile Heat Pump System at Low Ambient Temperature2018-01-007604/03/2018
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 Turbochargers2018-01-096604/03/2018
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
Optimization of the Engine Intake Air Temperature through the Air Conditioning Unit2018-01-097304/03/2018
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 Optimization of Compressor Rotor Clutch Sub-assembly Using Electro- Magnetic Analysis2018-01-048404/03/2018
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
Numerical Simulation of Oil Separator of an Automotive Swash Type Compressor2018-01-048804/03/2018
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
Development of a 48 V P0 Demonstration Vehicle with eBooster® Air Charging2018-01-041804/03/2018
The design of a demonstration vehicle is presented where improvements to the electrical and air induction systems are made which provide increased performance with improved fuel economy. This is made possible by a 48 V architecture which enables the deployment of new components, specifically a belted motor generator unit (MGU) and electrically-driven compressor (eBooster®). The synergy between these components enables energy efficient means to collect regenerated energy and provide added torque, faster engine response, and extended engine off operation among a list of added features. Control features and strategy are highlighted along with simulation and vehicle test data. Resultant performance and fuel economy benefits are reviewed which support the contention of 48 V being a cost effective architecture to enable CO2 reduction relative to a higher voltage hybrid.
Mohon, Sara, Van Maanen, Keith, Liu, Xiaobing, Keller, Philip, Griffen, Matthew, Negandhi, Varun
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
Study on Nonlinear Rotordynamics Characteristics for Electric Compound Turbocharger2017-01-241810/08/2017
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
A Comparison of On-Engine Surge Detection Algorithms using Knock Accelerometers2017-01-242010/08/2017
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
The Effect of Ported Shroud Recirculating Casing Treatment on Turbocharger Centrifugal Compressor Acoustics2017-01-179606/05/2017
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
Control-Oriented Compressor Model with Adiabatic Efficiency Extrapolation2017-01-103203/28/2017
Downsizing and turbocharging with single or multiple stages has been one of the main solutions to decrease fuel consumption and harmful exhaust emissions, while keeping a sufficient power output. An accurate and reliable control-oriented compressor model can be very helpful during the development phase, as well as for engine calibration, control design, diagnostic purposes or observer design. A complete compressor model consisting of mass flow and efficiency models is developed and motivated. The proposed model is not only able to represent accurately the normal region measured in a compressor map but also it is capable to extrapolate to low compressor speeds. Moreover, the efficiency extrapolation is studied by analyzing the known problem with heat transfer from the hot turbine side, which introduces errors in the measurements done in standard gas stands. Since the parameterization of the model is an important and necessary step in the modeling, a tailored parameterization approach is
Llamas, Xavier, Eriksson, Lars
Optimal Pressure Based Detection of Compressor Instabilities Using the Hurst Exponent2017-01-104003/28/2017
The compressor surge line of automotive turbochargers can limit the low-end torque of an engine. In order to determine how close the compressor operates to its surge limit, the Hurst exponent of the pressure signal has recently been proposed as a criterion. The Hurst exponent quantifies the fractal properties of a time series and its long-term memory. This paper evaluates the outcome of applying Hurst exponent based criterion on time-resolved pressure signals, measured simultaneously at different locations in the compression system. Experiments were performed using a truck-sized turbocharger on a cold gas stand at the University of Cincinnati. The pressure sensors were flush-mounted at different circumferential positions at the inlet of the compressor, in the diffuser and volute, as well as downstream of the compressor. Results show that the previously identified threshold value distinguishing between surge and stable operation when the analysis was carried out for a different and
Kerres, Bertrand, Mihaescu, Mihai, Gancedo, Matthieu, Gutmark, Ephraim
Ejector Energy-Saving Technology for Mobile Air Conditioning Systems2017-01-012003/28/2017
This study reports on a new generation ECS (Ejector Cycle System) which includes a highly efficient ejector and a novel system configuration. The ejector is working as a fluid jet pump that recovers expansion energy which is wasted in the conventional refrigeration cycle decompression process, and converts the recovered expansion energy into pressure energy and raises the compressor suction pressure. Consequently, the ejector system can reduce power consumption of the compressor by using the above mentioned pressure-rising effect and improve energy efficiency of the refrigeration cycle. The ejector consists of a nozzle, a suction section, a mixing section and a diffuser. The objective of this study is to improve actual fuel economy of all vehicles by ejector technology. The previous generation ECS was reported in 2012 SAE World Congress1. Now, a new generation ECS has been successfully developed and released in the market for Mobile Air Conditioning systems as of 2013. It achieves
Shan, Zhiwei, Kawamoto, Yoichiro, Ogata, Gota
Turbo Speed Estimation Using Fixed-Point Iteration2017-01-059103/28/2017
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
Automated Calibration for Compressor Recirculation Valve Control2017-01-059403/28/2017
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
A General Selection Method for the Compressor of the Hydrogen Internal Combustion Engine with Turbocharger2017-01-102503/28/2017
Hydrogen is a promising energy carrier because it is characterized by a fast combustion velocity, a wide range of sources, and clean combustion products. A hydrogen internal combustion engine (H2ICE) with a turbocharger has been used to solve the contradiction of power density and control NOx. However, the selection of a H2ICE compressor with a turbocharger is very different from traditional engines because of gas fuel. Hydrogen as a gas fuel has the same volume as its cylinder and thus increases pressure and reduces the mass flow rate of air in cylinder for a port fuel injection-H2ICE (PFI-H2ICE). In this study, a general method involving a H2ICE with a turbocharger is proposed by considering the effect of hydrogen on cylinders. Using this method, we can calculate the turbocharged pressure ratio and mass flow rate of air based on the target power and general parameters. This method also provides a series of intake temperatures of air before calculation to improve accuracy. The
Luo, Qinghe, Sun, Baigang, Wang, Xi
Heat Transfer Effect on Performance Map of a Turbocharger Turbine for Automotive Application2017-01-103603/28/2017
In the last few years, the effect of diabatic test conditions on compressor performance maps has been widely investigated leading some Authors to propose different correction models. The aim of the paper is to investigate the effect of heat transfer phenomena on the experimental definition of turbocharger maps, focusing on turbine performance. An experimental investigation on a small turbocharger for automotive application has been carried out and presented. The study focused onto the effects of internal heat transfer on turbine thermomechanical efficiency. The experimental campaign was developed considering the effect of different heat transfer state by varying turbine inlet temperature, oil and coolant temperature and compressor inlet pressure. An original model previously developed by the Authors is adopted for the correction of compressor steady flow maps. The major benefit of this method is represented by the easiness of data post-processing, the data base economy, the reduced
Marelli, Silvia, Gandolfi, Simone, Capobianco, Massimo
A Variable Displacement Supercharger Performance Evaluation2017-01-064003/28/2017
The Variable Displacement Supercharger (VDS) is a twin helical screw style compressor that has a feature to change its displacement and its compression ratio actively during vehicle operation. This device can reduce the parasitic losses associated with supercharging and improve the relative fuel economy of a supercharged engine. Supercharging is a boosting choice with several advantages over turbocharging. There is fast pressure delivery to the engine intake manifold for fast engine torque response providing the fun to drive feel. The performance delivered by a supercharger can enable engine fuel economy actions to include engine downsizing and downspeeding. The cost and difficulty of engineering hot exhaust components is eliminated when using only an air side compressor. Faster catalyst warm up can be achieved when not warming the turbine housing of a turbocharger. To quantify these effects, a 2.0L Ford Eco-Boost® engine was chosen for an analytical comparison of three boosting
Wade, Robert, Murphy, Steven, Cross, Paul, Hansen, Craig
Automotive A/C Servicing – Refrigerant Flushing of a Failed A/C System2017-01-016703/28/2017
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
Effects of Thinner Condenser Technology on Vehicle AC Pull Down Performance2017-01-016603/28/2017
The effects of substituting a 12 mm thick subcool on top condenser in place of a 16 mm subcool on bottom condenser are evaluated in a vehicle level AC pull down test. The A to B testing shows that a thinner condenser with subcool on top exhibits no degradation in AC performance while resulting in a lower total system refrigerant charge. The results are from vehicle level tests run in a climatically controlled vehicle level wind tunnel to simulate an AC pull down at 43°C ambient. In addition to cabin temperature and AC vent temperatures, comparison of compressor head pressures was also done. The conclusion of the study was that a standard 16 mm thick subcool on bottom IRD condenser can be replaced by a 12 mm thick subcool on top IRD condenser with no negative effects on performance.
Pandit, Noori
Investigation of a Dual HVAC MAC System with Three Row Ducts Using 1D Modeling2017-01-016403/28/2017
In an automotive air-conditioning (AC) system, upfront prediction of the cabin cool down rate in the initial design stage will help in reducing the overall product development (PD) time. Vehicle having higher seating capacity will have higher thermal load and providing thermal comfort to all passengers uniformly is a challenging task for the automotive HVAC (Heating Ventilation and Air conditioning) industry. Dual HVAC unit is generally used to provide uniform cooling to a large cabin volume. One dimensional (1D) simulation is being extensively used to predict the HVAC performance during the initial stage of PD. The refrigerant loop with components such as compressor, condenser, TXV and evaporator was modeled. The complicated vehicle cabin including the glazing surfaces and enclosures were modeled as a three row duct system using 1D tool AMESim®. The material type, density, specific heat capacity and thermal conductivity of the material were specified. The actual vehicle driving
Muthusamy, Venkatesan, Sathish Kumar, S., Sambandan, Saravanan
Vibration Fatigue for Chassis-Mounted, Cantilevered Components2017-01-036003/28/2017
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
Thermodynamic Potential of Electrical Turbocharging for the Case of Small Passenger Car ICE under Steady Operation2017-01-052603/28/2017
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
Energy Consumption of Passenger Compartment Auxiliary Cooling System Based on Peltier Effect2017-01-015503/28/2017
The closed cabin temperature is anticipated to be cooled down when it is a bit hot inside the driving car. The traditional air-condition lowers the cabin temperature by frequently switching the status of the compressor, which increases the engine’s parasitic power and shortens the compressor’s service-life. The semiconductor auxiliary cooling system with the properties of no moving parts, high control precision and quick response has the potential to assist the on-board air-condition in modulating the cabin temperature with relative small ranges. Little temperature differences between the cabin and the outside environment means that the system energy consumption to ensure the occupant comfort is relatively low and the inefficiency could be made up by the renewable energy source. This research focuses on the influence of the vehicle speed and the ambient temperature over the cooling energy consumption considering occupant heat dissipation in order to maximize the system energy
Xu, Yongbing, Tan, Gangfeng, Guo, Xuexun, Ping, Xianyao
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