Two-Zone Simulation of an Axial Vane Rotary Engine Cycle

An axial vane rotary engine (AVRE) is a novel type of rotary engines. The engine is a positive displacement mechanism that permits the four “stroke” action to occur in one revolution of the shaft with a minimum number of moving components in comparison to reciprocating engines. In this paper, a two-zone combustion model is developed for a spark ignition AVRE. The combustion chamber is divided into burned and unburned zones and differential equations are developed for the change in pressure and change in temperature in each zone. The modelling is based on equations for energy and mass conservation, equation of state, and burned mass fraction. The assumption is made that both zones are at the same pressure P, and the ignition temperature is the adiabatic flame temperature based on the mixture enthalpy at the onset of combustion. The developed code for engine simulation in MATLAB is applied to another engine and there is a good agreement between results of this code and results related to the engine chosen for validation, so the modelling is independent of configuration.

Numerical Study on Flow Field in a Peripheral Ported Rotary Engine Under the Action of Apex Seal Leakage

Apex seal leakage is one of the main defects restricting the performance improvement of rotary engines. The aim of this study is to study the airflow movement in a peripheral ported rotary engine under the action of apex seal leakage. For this purpose, a 3D dynamic calculation model considering apex seal leakage was firstly established and verified by particle image velocimetry data. Furthermore, based on the established 3D model, the flow field in the combustion chamber under the four apex seal leakage gaps (0.02, 0.04, 0.06 and 0.08 mms) and the three engine revolution speeds (2000, 3500, and 5000 RPMs) was calculated. By comparing with the flow field under the condition without leakage, the influences of the existence of apex seal leakage on the velocity field, the turbulent kinetic energy and the volumetric efficiency in the combustion chamber were investigated. Thereinto, the influences of the existence of apex seal leakage on the velocity field is that at the intake stroke, a vortex formed in the middle of the combustion chamber under the condition without apex seal leakage, was intensified by the apex seal leakage action. At the compression stroke, irrespective of the condition with or without apex seal leakage, all vortexes in the combustion chamber are gradually broken into a unidirectional flow. However, there is an obvious "leakage flow area" at the end of combustion chamber due to the existence of apex seal leakage.

Recent Studies of Fuels Used in Wankel Rotary Engines

During the decades past, the engine industries have witnessed a remarkable upsurge in the research and development (R&D) of modern technologies due to factors such as energy security and environmental concerns. Focus is on improved engine performance, sustainable energy, fuel economy, and minimal harmful exhaust emissions. Even though globally large database now captures modern engine technologies, a skillful presentation of those data is a demanding task. Based on this analogy, the authors made a conscious effort to brief audience on the various fuels used in Wankel rotary engine (RE) which is a type of internal combustion engine (ICE). Wankel REs various operating models, their merits, and demerits regarding modern engine technologies, the type of fuels and their utilization methods, and the future prospect of biofuel as its engine fuel has been made accessible in a subtle manner in this paper. In summary, this paper provides a wide scope review of basic principles that govern practical Wankel RE design and operation, the widely used single fuels and multi fuels in Wankel RE operation with their properties as well as emissions, and the practical Wankel RE design and operation in the present era and the prospects in the near future. It also outlines simplified frameworks of modern Wankel RE technologies structured in a systematic way to contribute to enhanced engine performance, sustainable energy, reduce fuel consumption, and reduce exhaust emissions in this pragmatic field.

Housing Profile Design for Improved Apex Seal Lubrication Using a Finite Length Roller Elastohydrodynamic Lubrication Model

Finite-length roller contacts are found in apex seal-housing interfaces in rotary engines, as well as in many other mechanical systems, such as those at the interfaces of meshing gear teeth, cam followers, and roller bearings. Rollers are usually designed with crowns and modified ends to mitigate the negative effects of misalignment, thermal deformation, and edge-induced non-uniform displacement. A crowned-roller elastohydrodynamic lubrication model is enriched and employed to investigate seven housing surface profiles, including a sinusoidal recess, sinusoidal ends, the combination design of a sinusoidal recess and sinusoidal ends, multiple sinusoidal recesses, a concave shape, and a concave shape with sinusoidal ends or round corners, aiming to improve the tribological performance of the interface via increasing the minimum film thickness but reducing the average and maximum film thicknesses, and lowering friction coefficient. The modified discrete convolution and fast Fourier transform method with duplicated padding is utilized to deal with the potential free-end-surface effect. The simulation results suggest that the combinations of a concave shape and sinusoidal ends, or round corners, are the best designs because they can help distribute the lubricant most uniformly without causing a negative edge effect.

Prospects for the use of rotary engines

The possibility of using rotary piston engines for various industries is analyzed. Keywords transport vehicle, piston engine, crankand-rod mechanism, rotary vane engines. [email protected]