Automotive Engine Friction and Fuel Efficiency—Viscous Versus Non-Viscous Effects

2009 ◽  
pp. 75-75-21 ◽  
Author(s):  
PJ Ghirla ◽  
RK Smith
Keyword(s):  
Fuel Efficiency ◽  
Viscous Effects ◽  
Automotive Engine ◽  
Engine Friction

Paper 7: An Experimental Analysis of the Cold Cranking Resistance of an Automotive Engine

1966 ◽  
Vol 181 (15) ◽  
pp. 177-183
Author(s):  
W. C. Pike ◽  
O. Haisell
Keyword(s):  
Motor Development ◽  
Low Temperatures ◽  
Shear Stresses ◽  
Oil Viscosity ◽  
General Application ◽  
Automotive Engine ◽  
Starter Motor ◽  
Engine Friction ◽  
Work Done ◽  
Piston Assembly

A study has been made of the total engine friction, the piston assembly friction, and the unrecovered work done on the gases in a four-cylinder automotive engine cranked at low temperatures with its starter motor. Development of the instrumentation is briefly described, and the results obtained with a range of single and multigrade lubricating oils, at temperatures between 0 and 42°F, are given. The effect of oil viscosity (determined in a Ferranti–Shirley cone-and-plate viscometer) on the various losses was studied. Piston assembly friction, measured without the cylinder head in position, accounted for between 40 and 50 per cent of the engine friction and was predominantly viscous. The effect of pressure acting on the pistons was to increase the engine friction only slightly at the higher temperatures; unrecovered work done on the gases was a very important cause of cranking resistance and did not vary with oil viscosity. Shear stresses measured in the engine at the lower temperatures were higher than could be reached in the viscometer. The viscometer may, therefore, not have a general application for predicting the cranking resistance of non-Newtonian oils.

Advanced Automotive Engine Thermal Management: Simplified Diesel Engine Model and Experimental Validation

2005 ◽  
Author(s):  
Christopher J. Simoson ◽  
John R. Wagner
Keyword(s):  
Thermal Management ◽  
Rural Areas ◽  
Internal Combustion Engines ◽  
Fuel Efficiency ◽  
Engine Performance ◽  
Exhaust Gas ◽  
Combustion Chemistry ◽  
Automotive Engine ◽  
Power Characteristics ◽  
Engine Model

Diesel engines fulfill diverse demands in urban and rural areas throughout the world. While the advantages of compression ignition engines are superior to other internal combustion engines in torque generation and fuel efficiency, some diesel exhaust emissions pose health and environmental problems. Emission reduction techniques generally diminish one type of tailpipe gas yet often sacrifice engine performance and may even raise other emission levels. For instance, exhaust gas recirculation can reduce NOx emissions. However, the dilution of the combustion charge with hot inert exhaust gas hinders the engine’s power characteristics. To solve this problem, an EGR cooler allows the exhaust gases to be cooled prior to mixing with intake air allowing a denser cylinder charge for combustion. The effective application of cooled EGR requires a smart thermal management system. In this paper, a real time empirical and analytical model will be introduced to estimate the diesel engine’s overall performance. The simplified model considers the engine’s combustion chemistry, as well as the thermal, emissions, and rotational dynamics. Representative numerical and experimental test results are presented and discussed to validate the model. Eventually, an on-board computer controller will use this model to regulate the EGR valve’s functionality and the smart thermal system.

ANALYSIS OF COMPETING VARIANTS OF AIR CONDITIONING SYSTEMS WITHOUT AIR EXTRACTION FROM ENGINES AT THE STAGE OF PASSENGER AIRCRAFT ONBOARD SYSTEMS CONCEPTUAL DESIGN

2019 ◽  
Vol 6 (3) ◽  
pp. 80-85
Author(s):  
Denis Igorevich Smagin ◽  
Konstantin Igorevich Starostin ◽  
Roman Sergeevich Savelyev ◽  
Anatoly Anatolyevich Satin ◽  
Anastasiya Romanovna Neveshkina ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Air Conditioning ◽  
Research University ◽  
Cooling System ◽  
Fuel Efficiency ◽  
Air Cooling ◽  
Moscow Aviation Institute ◽  
Air Conditioning System ◽  
Low Efficiency ◽  
Air Conditioning Systems

One of the ways to achieve safety and comfort is to improve on-board air conditioning systems.The use of air cooling machine determines the air pressure high level at the point of selection from the aircraft engine compressor. Because of the aircraft operation in different modes and especially in the modes of small gas engines, deliberately high stages of selection have to be used for ensuring proper operation of the refrigeration machine in the modes of the aircraft small gas engines. Into force of this, most modes of aircraft operation have to throttle the pressure of the selected stage of selection, which, together with the low efficiency of the air cycle cooling system, makes the currently used air conditioning systems energy inefficient.A key feature of the architecture without air extraction from the main engines compressors is the use of electric drive compressors as a source of compressed air.A comparative analysis of competing variants of on-board air conditioning system without air extraction from engines for longrange aircraft projects was performed at the Moscow Aviation Institute (National Research University).The article deals with the main approaches to the decision-making process on the appearance of a promising aircraft on-board air conditioning system at the stage of its conceptual design and formulated the basic requirements for the structure of a complex criterion at different life cycle stages.The level of technical and technological risk, together with a larger installation weight, will require significant costs for development, testing, debugging and subsequent implementation, but at the same time on-board air conditioning system scheme without air extraction from the engines will achieve a significant increase in fuel efficiency at the level of the entire aircraft.

Microstructural and Mechanical Behaviour Evaluation of Mg-Al-Zn Alloy Friction Stir Welded Joint

2020 ◽  
Vol 17 (3) ◽  
pp. 8150-8159
Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh
Keyword(s):  
Heat Treatment ◽  
Friction Stir Welding ◽  
Magnesium Alloys ◽  
Mechanical Performance ◽  
Fuel Efficiency ◽  
Research Work ◽  
Grain Structure ◽  
Tensile Fracture ◽  
Friction Stir ◽  
The Impact

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.

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