LAUSR

The working chamber volume and pressure constructed from involute of variable radii circle with line-arcs modification are calculated accurately by equivalent translation area method avoiding complicated piece-wise integration and Green’s theorem. The influence of modified distance is divided into two benchmarks to investigate because the interval length of the discharge process is always 2π. The increase of modified distance will decrease the working chamber volume before the discharge process and increase the volume in the discharge process. Afterward, the volume change rate is proposed to study the tangent slope of volume curve, which is also meaningful for discussing the working chamber pressure. Finally, the working chamber pressure is obtained by the working chamber volume. The increase of modified angle and distance will increase the working chamber pressure in the same orbiting angle before the discharge process, but decrease the discharge pressure and advance the discharge process. Furthermore, the influences of modified parameters on the working chamber pressure in the discharge process are qualitatively studied. The increase of modified parameters will decrease the working chamber pressure in the discharge process.