Simulation of the Performance of a Twin-Rotor Piston Engine

2013 ◽  
Vol 376 ◽  
pp. 360-365
Author(s):  
Teng An Zou ◽  
Cun Yun Pan ◽  
Hai Jun Xu ◽  
Xiang Zhang

A comprehensive computer simulation has been developed to predict the performance of a twin-rotor piston engine (TRPE) by means of the zero-dimensional thermodynamic model. With the given model, the chamber mass, pressure and temperature are available during a complete engine cycle. The results are consistent with the TRPE’s working cycle trend. By the chamber pressure, the overall engine performance parameters can be calculated. The model can be used as an analytical tool for preliminary design and development of the TRPE.

2013 ◽  
Vol 853 ◽  
pp. 553-558
Author(s):  
Hu Chen ◽  
Cun Yun Pan ◽  
Teng An Zou

Twin-rotor cylinder-embedded piston engine are a high power density and no valve mechanism engine. Given the motion law of two rotors sine curve change, its kinematic model of rod can be established, and key parameters of rod related to engine performance, such as angular displacement, velocity and acceleration of rod are presented. And then the kinematic model of rod is imported into MATLAB, the moving law of angular displacement, velocity and acceleration of rod are analyzed by changing the value of swing amplitude k. It can be concluded that the changes of rods motion are periodic, relatively gentle, and the periodic of angular displacement, velocity and acceleration of rod are the same. For different value of k, the fluctuation of velocity and acceleration of rod are in direct proportion to k and angular displacement of rod is fixed.


Author(s):  
Dibo Pan ◽  
Haijun Xu ◽  
Bolong Liu ◽  
Congnan Yang

The sealing characteristics of an annular power cylinder based on the Twin-rotor piston engine are studied, which provides a theoretical foundation for the sealing design of a new high-power density piston engine. In this paper, the basis thermodynamic realization process of an annular power cylinder is presented. The Runge Kutta equation is used to establish the coupled leakage model of adjacent working chambers under annular piston seal. And the sealing performance of the annular power cylinder is analyzed in detail. Moreover, the influence of rotor speed and compression ratio on the sealing characteristics and leakage is studied. Finally, some tests are carried out to verify the sealing principle and simulation results, which verifies the theoretical basis of simulation analysis. Results show that there are double pressure peaks in the leakage chamber between two working chambers, which is beneficial to reduce the leakage rate. Besides, increasing the speed and decreasing the compression ratio can help to reduce gas leakage. Furthermore, the effects of speed variation on the leakage are only significant when rotating at low speed. Changing the compression ratio has a greater effect on the slope of the leakage curve at a low compression ratio, and the lower the compression ratio, the better the sealing effect.


2013 ◽  
Vol 29 (4) ◽  
pp. 788-799 ◽  
Author(s):  
S. Menon ◽  
Christopher P. Cadou

Author(s):  
Dimitrios Chatzianagnostou ◽  
Stephan Staudacher

Abstract Hecto pressure composite cycle engines with piston engines and piston compressors are potential alternatives to advanced gas turbine engines. The nondimensional groups limiting their design have been introduced and generally discussed in Part I [1]. Further discussion shows, that the ratio of effective power to piston surface characterizes the piston thermal surface load capability. The piston design and the piston cooling technology level limit its range of values. Reynolds number and the required ratio of advective to diffusive material transport limit the stroke-to-bore ratio. Torsional frequency sets a limit to crankshaft length and hence cylinder number. A rule based preliminary design system for composite cycle engines is presented. Its piston engine design part is validated against data of existing piston engines. It is used to explore the design space of piston components. The piston engine design space is limited by mechanical feasibility and the crankshaft overlap resulting in a minimum stroke-to-bore ratio. An empirical limitation on stroke-to-bore ratio is based on existing piston engine designs. It limits the design space further. Piston compressor design does not limit the piston engine design but is strongly linked to it. The preliminary design system is applied to a composite cycle engines of 22MW take-off shaft power, flying a 1000km mission. It features three 12-cylinder piston engines and three 20-cylinder piston compressors. Its specific fuel consumption and mission fuel burn are compared to an intercooled gas turbine with pressure gain combustion of similar technology readiness.


2021 ◽  
Author(s):  
Marek Vorlíček ◽  
◽  
Jozef Čerňan

This paper explains the basic definition of ignition, combustion and description of the ignition system functionality. The ignition systems are divided according to established criteriums into the most used types and descriptions of each ignition system components. It focuses on ignition timing and circumstances that affect it and how they influence the observed parameters. I am using ignition timing as an instrument for the observation and optimization of ignition. These practices are tested on piston engine in the practical part of this paper. It describes the modification of the timing curve, measuring of engine power and comparison between each curve. It is an analysis of engine performance under different conditions. The most efficient timing curve is chosen and further evaluated. The used engine for this paper was a rebuild from a car engine used in Trabant 601, VEB Automobilwerke automobile.


Author(s):  
Vassili V. Toropov ◽  
Henrik Carlsen

Abstract The ideal Stirling working cycle has the maximum obtainable efficiency defined by Carnot efficiency, and highly efficient Stirling engines can therefore be built, if designed properly. To analyse the power output and the efficiency of a Stirling engine, numerical simulation programs (NSP) have been developed, which solve the thermodynamic equations. In order to find optimum values of design variables, numerical optimization techniques can be used (Bartczak and Carlsen, 1991). To describe the engine realistically, it is necessary to consider several tens of design variables. As even a single call for NSP requires considerable computing time, it would be too time consuming to use conventional optimization techniques, which require a very large number of calls for NSP. Furthermore, objective and constraint functions of the optimization problem present some level of noise, i.e. can only be estimated with a finite accuracy. To cope with these problems, the multipoint explicit approximation technique is used.


Author(s):  
Sebastian Wittwer ◽  
Ivo Sandor

Abstract Recent developments in turbocharged gasoline engines have established new requirements for the turbine. A simple approach of scaling or optimizing existing turbines on component level might not be sufficient in terms of finding an optimal solution according to the multi-point, multi-disciplinary layout target. In the following paper nondimensional functional parameters are derived from turbomachinery analytics and rated on corresponding values of existing turbine stages. The influence of different parameters on aerodynamic performance is discussed based on CFD results and arranged according to their sensitivity for different engine relevant operating conditions. A metamodel for the preliminary design of variable nozzle turbine stages is derived from DoE (Design of Experiments) based CFD results. It is evaluated regarding its predictive quality on several exemplary turbine stages. Both, CFD and experimental results are therefore used while the experimental results are made up of hot gas stand measurements as well as measurements on engine test bench. Thus, not only the influence of functional parameters can be verified on turbine efficiency characteristics, but beyond that also the predictive quality of engine performance can be assessed.


2019 ◽  
Vol 252 ◽  
pp. 05007 ◽  
Author(s):  
Łukasz Grabowski ◽  
Ksenia Siadkowska ◽  
Krzysztof Skiba

This paper reports the results of simulation works of Rotax 912 aircraft piston engine, which is a basic unit in most ultra-light aircrafts. The method for preparing the model aircraft engine operation process was presented. Simulation tests were carried out in the AVL Boost programme. The programme allows a full use of zero-dimensional and one-dimensional modelling. It also allows a comparison of other engine models. The developed model has enabled us to simulate the flow of air through the inlet pipes, carburettors, valves and combustion process. The preparation of the model required us to enter parameters that are not available in the manufacturer's catalogue, therefore, necessary measurements and analysis of the engine parts were carried out on a laboratory bench. The calculations in the AVL Boost programme were carried out in the conditions determined for the selected BMEP values with the objective of characterising the engine performance by determining its power, torque and fuel consumption.


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