Development of a Stiffness-Based Chemistry Load Balancing Scheme, and Optimization of I/O and Communication, to Enable Massively Parallel High-Fidelity Internal Combustion Engine Simulations

2015 ◽  
Author(s):  
Janardhan Kodavasal ◽  
Kevin Harms ◽  
Priyesh Srivastava ◽  
Sibendu Som ◽  
Shaoping Quan ◽  
...  
Keyword(s):  
Load Balancing ◽  
Combustion Engine ◽  
Mesh Size ◽  
Test Case ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Simulation ◽  
Output Performance ◽  
Crank Angle ◽  
Blue Gene

A closed-cycle gasoline compression ignition engine simulation near top dead center (TDC) was used to profile the performance of a parallel commercial engine computational fluid dynamics code, as it was scaled on up to 4096 cores of an IBM Blue Gene/Q supercomputer. The test case has 9 million cells near TDC, with a fixed mesh size of 0.15 mm, and was run on configurations ranging from 128 to 4096 cores. Profiling was done for a small duration of 0.11 crank angle degrees near TDC during ignition. Optimization of input/output performance resulted in a significant speedup in reading restart files, and in an over 100-times speedup in writing restart files and files for post-processing. Improvements to communication resulted in a 1400-times speedup in the mesh load balancing operation during initialization, on 4096 cores. An improved, “stiffness-based” algorithm for load balancing chemical kinetics calculations was developed, which results in an over 3-times faster run-time near ignition on 4096 cores relative to the original load balancing scheme. With this improvement to load balancing, the code achieves over 78% scaling efficiency on 2048 cores, and over 65% scaling efficiency on 4096 cores, relative to 256 cores.

Development of a Stiffness-Based Chemistry Load Balancing Scheme, and Optimization of Input/Output and Communication, to Enable Massively Parallel High-Fidelity Internal Combustion Engine Simulations

2016 ◽  
Vol 138 (5) ◽  
Author(s):  
Janardhan Kodavasal ◽  
Kevin Harms ◽  
Priyesh Srivastava ◽  
Sibendu Som ◽  
Shaoping Quan ◽  
...  
Keyword(s):  
Load Balancing ◽  
Combustion Engine ◽  
Mesh Size ◽  
Test Case ◽  
Compression Ignition ◽  
Input Output ◽  
Engine Simulation ◽  
Crank Angle ◽  
Computational Fluid Dynamics Cfd ◽  
Blue Gene

A closed-cycle gasoline compression ignition (GCI) engine simulation near top dead center (TDC) was used to profile the performance of a parallel commercial engine computational fluid dynamics (CFD) code, as it was scaled on up to 4096 cores of an IBM Blue Gene/Q (BG/Q) supercomputer. The test case has 9 × 106 cells near TDC, with a fixed mesh size of 0.15 mm, and was run on configurations ranging from 128 to 4096 cores. Profiling was done for a small duration of 0.11 crank angle degrees near TDC during ignition. Optimization of input/output (I/O) performance resulted in a significant speedup in reading restart files, and in an over 100-times speedup in writing restart files and files for postprocessing. Improvements to communication resulted in a 1400-times speedup in the mesh load balancing operation during initialization, on 4096 cores. An improved, “stiffness-based” algorithm for load balancing chemical kinetics calculations was developed, which results in an over three-times faster runtime near ignition on 4096 cores relative to the original load balancing scheme. With this improvement to load balancing, the code achieves over 78% scaling efficiency on 2048 cores, and over 65% scaling efficiency on 4096 cores, relative to 256 cores.

The Compression-Ignition Engine and Its Applicability to British Railway Traction

1933 ◽  
Vol 124 (1) ◽  
pp. 3-61 ◽  
Author(s):  
L. F. R. Fell
Keyword(s):  
Internal Combustion Engine ◽  
High Speed ◽  
Combustion Engine ◽  
Internal Combustion ◽  
High Rate ◽  
Wide Field ◽  
Compression Ignition ◽  
Electric Locomotive ◽  
Compression Ignition Engine ◽  
Railway Traction

The author considers that, while the internal combustion engine is not universally applicable to British railway traction, there is a wide field which can be more economically covered by the oil engine than by other means. Electric transmission is, in spite of high first cost, the most readily adaptable for use in conjunction with the oil engine, and possesses a balance of advantages over all other known systems. The oil-electric locomotive offers a long list of important advantages for railway operation not possessed by other systems. These advantages are, however, offset by high first cost for powers of 1,000 b.h.p. and over. A comparison is drawn between the first cost of steam and oil-electric locomotives for the various duties called for in the service of a British railway. This shows that, while the first cost of the oil-electric main line express passenger locomotive is three times that of the existing steam locomotive, the first costs of branch passenger, medium goods, and shunting steam and oil-electric engines are comparable. This is owing to the cost per brake horse-power required diminishing with increase of size in the case of the steam locomotive, whereas it remains constant in the case of the oil-electric. Owing to the high rate of acceleration necessary the use of the oil-electric system is considered unsuitable as a substitute for dependent electrification of suburban lines. The railway oil engine is a specialized requirement. It must be of the high-speed type running at speeds of up to 1,500 r.p.m., in order to reduce first cost and for other reasons. Details are given of various types of British compression-ignition engines which are considered suitable for British railway work. The author deduces that an engine of twelve-cylinder “V” type and an engine with six cylinders in line, both incorporating the same design and size of cylinder, would fill all the requirements which can be economically met by the oil engine on a British railway. He selects the single sleeve-valve engine design as having the greatest balance of advantages in its favour for railway purposes. Attention is drawn to the importance of simplifying the installation of the compression-ignition engine and various suggestions are put forward to this end. In conclusion the author stresses the importance of the railway companies giving a lead to the internal combustion engine industry as to the railway requirements in size and type of engine, and states that it is the purpose of his paper to assist those concerned in arriving at this immediately important decision.

scholarly journals Experimental Research on Controllability and Emissions of Jet-Controlled Compression Ignition Engine

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2936 ◽  
Author(s):  
Hua Tian ◽  
Jingchen Cui ◽  
Tianhao Yang ◽  
Yao Fu ◽  
Jiangping Tian ◽  
...  
Keyword(s):  
Thermal Efficiency ◽  
High Speed ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Engine Emissions ◽  
Spark Timing ◽  
Crank Angle ◽  
Marine Engines ◽  
Si Engines ◽  
Ci Engines

Low-temperature combustions (LTCs), such as homogeneous charge compression ignition (HCCI), could achieve high thermal efficiency and low engine emissions by combining the advantages of spark-ignited (SI) engines and compression-ignited (CI) engines. Robust control of the ignition timing, however, still remains a hurdle to practical use. A novel technology of jet-controlled compression ignition (JCCI) was proposed to solve the issue. JCCI combustion phasing was controlled by hot jet formed from pre-chamber spark-ignited combustion. Experiments were done on a modified high-speed marine engine for JCCI characteristics research. The JCCI principle was verified by operating the engine individually in the mode of JCCI and in the mode of no pre-chamber jet under low- and medium-load working conditions. Effects of pre-chamber spark timing and intake charge temperature on JCCI process were tested. It was proven that the combustion phasing of the JCCI engine was closely related to the pre-chamber spark timing. A 20 °C temperature change of intake charge only caused a 2° crank angle change of the start of combustion. Extremely low nitrogen oxides (NOx) emission was achieved by JCCI combustion while keeping high thermal efficiency. The JCCI could be a promising technology for dual-fuel marine engines.

scholarly journals Numerical study of effects of the intermediates and initial conditions on flame propagation in a real homogeneous charge compression ignition engine

2014 ◽  
Vol 18 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Meng Zhang ◽  
Jinhua Wang ◽  
Zuohua Huang ◽  
Norimasa Iida
Keyword(s):  
Equivalence Ratio ◽  
Initial Temperature ◽  
Exhaust Gas Recirculation ◽  
Flame Speed ◽  
Exhaust Gas ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Crank Angle ◽  
Increase Rate ◽  
Gas Recirculation

The premixed flame speed under a small four stock homogeneous charge compression ignition engine, fueled with dimethyl ether, was investigated. The effects of intermediate species, initial temperature, initial pressure, exhaust gas recirculation, and equivalence ratio were studied and compared to the baseline condition. Results show that, under all conditions, the flame speeds calculated without intermediates are higher than those which took the intermediates in consideration. Flame speeds increase with the increase of crank angle. The increase rate is divided into three regions and the increase rate is obviously high in the event of low temperature heat release. Initial temperature and pressure only affect the crank angle of flame speed, but have little influence on its value. Equivalence ratio and exhaust gas recirculation ratio do not only distinctly decrease the flame speed, but also advance the crank angle of flame speed.

Dynamic Pressure Measurement and Uncertainty Analysis Using a Piezoelectric Transducer for a Combustion Engine

2016 ◽  
Vol 827 ◽  
pp. 77-82 ◽  
Author(s):  
Andrzej Bąkowski ◽  
Leszek Radziszewski ◽  
Milan Žmindák
Keyword(s):  
Pressure Measurement ◽  
Combustion Engine ◽  
Dynamic Pressure ◽  
Type A ◽  
Standard Uncertainty ◽  
Maximum Pressure ◽  
Compression Ignition ◽  
Compression Ignition Engine ◽  
Dynamic Pressure Measurement ◽  
Engine Type

This paper analyses the uncertainty of pressure measurements in-cylinder and in injection pipe conducted during the studies of a compression ignition engine. Type A and type B evaluations were used to determine the uncertainties of the results. The results are presented for the engine running on diesel or bio-fuel and operating under full load conditions. The results of normality tests provide grounds to reject H0 in some cases. Slightly lower standard uncertainty of the maximum pressure measurement calculated using type A evaluation were acquired for the engine running on bio-fuel.

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