Paper 7: The Prediction of Diesel Engine Performance and Combustion Chamber Component Temperatures Using Digital Computers

Author(s):  
M. S. Janota ◽  
A. J. Hallam ◽  
E. K. Brock ◽  
S. G. Dexter

The development of digital programs for predicting the performance of multi-cylinder, turbo-charged diesel engines, and the temperature distribution in engine components is described. The performance program incorporates the relatively simple ‘filling and emptying’ method, with the turbo-charger compressor and turbine as boundary conditions, to calculate transient gas conditions. In the second part of the paper a description is given of the metal temperature program assumptions and use, including the deduction of the surrounding fluid conditions. The accuracy and limitations of the performance program is demonstrated by comparing predictions and measurements on an experimental 2-stroke single cylinder diesel engine operating under simulated turbo-charged conditions. The practical applications of the programs to medium speed 2- and 4-stroke engines are illustrated, and the economics of their use as a design aid are discussed.

Author(s):  
Fan Su ◽  
Malcolm Payne ◽  
Manuel Vazquez ◽  
Peter Eggleton ◽  
Alex Vincent

Biodiesel blends were prepared by mixing low sulphur #2 diesel and biodiesel of two origins (canola and frying oil) at two different concentrations (5% and 20%). They were tested in a single-cylinder four-stroke medium-speed diesel engine under three engine modes representing idle, about 50% power and full load conditions. Engine performance and emissions data obtained with the blends were compared to that of engine running with the #2 diesel. Results indicated that the 5% blends could maintain engine power and fuel economy. Frying oil based B5 provided more significant reductions on CO, THC and PM emissions and increments on NOx emissions as compared with that of the canola B5 fuel. The 20% blends reduce engine CO, PM and smoke emissions, but increase NOx emissions by up to approximately 8%. Engine cylinder pressure and injection pressure data was also collected to provide additional information for evaluation of fuel economy and emissions benefits of using the blends.


1989 ◽  
Vol 111 (3) ◽  
pp. 516-520 ◽  
Author(s):  
B. D. Hsu ◽  
G. L. Leonard ◽  
R. N. Johnson

Coal-water-slurry (CWS) engine tests designed to evaluate a new accumulator-based injection system are described in this paper. The new injection system was found to improve CWS burnout considerably at both full and part engine loads. The peak cylinder firing pressure when operating with CWS was no higher than when operating with diesel oil. These data demonstrate the improved engine performance that can be achieved with the accumulator-based injection system.


Author(s):  
Girish Parvate-Patil ◽  
Manuel Vasquez ◽  
Malcolm Payne

This paper emphasizes on the effects of different biodiesels and diesel on; heat release, ignition delay, endothermic and exothermic reactions, NOx, fuel injection pressure due to the fuel’s modulus of elasticity and cylinder pressure. Two 100% biodiesel and its blends of 20% with of low sulfur #2 diesel, and #2 diesel are tested on a single cylinder diesel engine under full load condition. Engine performance and emissions data is obtained for 100% and 20% biodiesels blends and #2 diesel. Testes were conducted at Engine Systems Development Centre, Inc. (ESDC) to evaluate the effects of biodiesel and its blends on the performance and emissions of a single-cylinder medium-speed diesel engine. The main objective of this work was to gain initial information and experience about biodiesel for railway application based on which biodiesel and its blends could be recommended for further investigation on actual locomotives.


10.14311/1169 ◽  
2010 ◽  
Vol 50 (2) ◽  
Author(s):  
J. Cisek

This paper presents ways of using the fully-digitised triggerable AVL VideoScope 513D video system for analysing the injection and combustion inside a diesel engine cylinder fuelled by RME with water emulsions.The research objects were: standard diesel fuel, rapeseed methyl ester (RME) and RME – water emulsions. With the aid of a helical flow reactor, stable emulsions with the water fraction up to 30 % weight were obtained, using an additive to prevent the water from separating out of the emulsion.An investigation was made of the effect of the emulsions on exhaust gas emissions (NOX, CO and HC), particulate matter emissions, smoke and the fuel consumption of a one-cylinder HD diesel engine with direct injection. Additionally, the maximum cylinder pressure rise was calculated from the indicator diagram. The test engine was operated at a constant speed of 1 600 rpm and 4 bar BMEP load conditions. The fuel injection and combustion processes were observed and analysed using endoscopes and a digital camera. The temperature distribution in the combustion chamber was analysed quantitatively using the two-colour method. The injection and combustion phenomena were described and compared.A way to reduce NOX formation in the combustion chamber of diesel engines by adding water in the combustion zone was presented. Evaporating water efficiently lowers the peak flame temperature and the temperature in the post-flame zone. For diesel engines, there is an exponential relationship between NOX emissions and peak combustion temperatures. The energy needed to vaporize the water results in lower peak temperatures of the combusted gases, with a consequent reduction in nitrogen oxide formation. The experimental results show up to 50 % NOX emission reduction with the use of 30% water in an RME emulsion, with unchanged engine performance.


Author(s):  
Yuzhi Jin ◽  
Yuping Qian ◽  
Yangjun Zhang ◽  
Weilin Zhuge

The Diesel–Brayton combined cycle engine was proposed previously to achieve the goal of lower fuel consumption, higher power density and good startup performance under low-temperature conditions. The prototype engine was designed and tested based on an off-the-shelf gas turbine and a diesel engine. To achieve a more compact and lighter design, the air supply system was designed based on the centrifugal compressor of the gas turbine. In the coupling operation mode aiming to generate the maximum power, a large amount of compressed air must be extracted into the diesel engine. The present paper presents the design methodology of the compact air supply system. The bleeding slot configuration was selected based on a parametric study and proven by systematic experiments. Three-dimensional simulations were conducted to investigate the performance and flow field of the compressor. Backflow appeared in several passages of the axial diffuser caused by air bleeding, which further distorted the air flow in the combustion chamber. Such distortion may cause compressor and combustion instabilities. In the future, the combustion chamber and the axial diffuser must be designed in combination with an air bleeding system to improve the engine performance.


Author(s):  
P Ramaswamy ◽  
S Seetharamu ◽  
K B R Verma ◽  
N Raman ◽  
K J Rao

8%Y2O3-stabilized zirconia (8YPSZ) and mullite (3Al2O3·2SiO2) powders, which were made plasma sprayable by using an organic binder (polyvinyl alcohol), have been plasma spray coated on to the piston head, valves and cylinder head of a 3.8kW single-cylinder diesel engine, previously coated with Ni-Cr-Al-Y bond coat. The engine with components coated with 250 μm thick 8YPSZ and 1 mm thick mullite thermal barrier coatings has been evaluated for fuel efficiency and for endurance during 500 h long rigorous tests. Improved fuel efficiency was shown by the engine with coated components and the results are discussed. The coatings and the coated components have also been examined for phases, microstructure and chemical composition by X-ray diffractometry (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). Mullite coatings were found to exhibit increased resistance to microcracking compared with 8YPSZ during the 500 h endurance test.


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