Modelling and simulation of working processes in Wankel engine with direct hydrogen injection system

Władysław Mitianiec

doi:10.19206/ce-116890

Abstract

Wankel engines were very attractive in automotive sector almost forty years ago because of small dimensions, compactness, simple design, smoothness of engine work and lack of vibration caused by inertia forces. The disadvantage of such engine was very high pollution, especially of hydrocarbons and carbon monoxide and high fuel consumption. These disadvantages can be eliminated by applying of direct injection of hydrogen and in the aviation sector by applying of fuel with high octane number also at a direct injection system. The main objective of the work is modelling of the thermodynamic process taking place during the scavenge process in such engine. At assumed geometry of the engine, initial and boundary conditions the change of engine parameters such as pressure, temperature, density, heat exchange and volume are calculated on the base of zero-dimensional model as a function of rotation angle of the piston. Forming of the mixture during fuel injection process in compression process gives information about the air excess ratio. The presented model is applicable for different sort of fuels. This work is introduction to a broader analysis of the processes in spatial system. Application of hydrogen reduces of toxic components emission from such engine, but decreases also engine power.

Highlights

History of rotary Wankel engine [2] is very long and expectations for it were very large
Working principles of that engine were described in many papers and elaborations [1, 7, 8, 15] concerning geometry, trajectory of the rotary piston and sealing
The engine has an advantage over four stroke engine that it can take several work cycles during one piston rotation for one piston depending on engine design

Summary

Introduction

History of rotary Wankel engine [2] is very long and expectations for it were very large. Working principles of that engine were described in many papers and elaborations [1, 7, 8, 15] concerning geometry, trajectory of the rotary piston and sealing. Features of this engine include: smoother rotational speed as a result of smaller inertia forces, higher rotational speed, smaller size in comparison to traditional valve engines, high specific power density, multifuel capability and compactness. The engine has an advantage over four stroke engine that it can take several work cycles (usually three) during one piston rotation for one piston depending on engine design.

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Results

Conclusion