Three-dimensional numerical analysis on combustion performance and flow of hybrid rocket motor with multi-segmented grain

This paper presents the combustion characteristics in hybrid rocket motors with multisegmented grain through three-dimensional numerical simulations.Multi-segmented grain is composed of several thin grains with two or more ports.The numerical model consists of Navier-Stokes equations with turbulence,solid fuel pyrolysis,chemical reactions,a fluid–solid coupling model and a regression rate model.The simulations adopt 90%Hydrogen Peroxide(HP)and PolyEthylene(PE)as the propellant combination.The effects of the rotation,port number,fuel grain segment number and mid-chamber length on the flow field and combustion performances are analyzed.The results indicate that the multi-segmented grain configuration can strengthen the flow field,and the regression rate and combustion efficiency are enhanced.Take the cases with two grain segments and three ports for example,the regression rate is increased by 32.4%-45.1%and the combustion efficiency increases by 6%-8.6%in different rotation angles.