Design method of axisymmetric basic flowfield with controlled expansion law

In order to make the design methodology of streamline traced nozzle more flexible, an innovative axis symmetrical basic flow field design methodology with controlled expansion law on wall was explored while a centre body was placed in the flowfield. In the design process, Method of characteristics (MOC) was used to inversely solve the wall with given expansion law. The main design parameters, such as expansion law, centre body and oblique angle, were parametrically investigated. Then the variation of structure and performance of basic flowfield with these parameters were obtained. Using this basic flowfield, a rectangular streamline traced nozzle was designed and analyzed. Results show that, inverse design can be achieved by MOC; when the inlet and exit flow parameters are stable, there is a suitable expansion law corresponding to the maximum thrust performance. The radius of centre body and length ratio of basic flowfield, with less effect on thrust, can be used as the parameters to optimize the moment characteristics of derivative nozzle. When the oblique angle increases, the length and thrust of basic flowfield decrease rapidly, so the choice of oblique angle should be considered carefully.