A new model for hybrid rocket combustion
- Paper ID
1980-IAF-F-247
- author
- company
Chung Shan Institute of Science and Technology
- country
Republic of China
- year
1980
- abstract
For investigating the hybrid rocket combustion, the problem involving flow of a turbulent boundary layer with mass injection and combustion is further studied. The Spalding's eddy-break-up concept is adopted in this paper to solve the species conservation equation of fuel. Replacing the assumption of flame sheet taken by Cherng-Tao's model, the -flame zone model is employed to propose a combined model for determining the eddy viscosity such that the turbulent boundary layer is divided into inner and outer regions. In the inner region near the wall,the Cebeci's model for eddy viscosity is modified to allow for mass injection and combustion, and the region is subdivided into three subregions as lower inner region, flame zone region due to the ignition temperature of mixture and upper inner region. This is different from the Cherng-Tao's model and also a new concept of this paper. In the outer region of the turbulent boundary layer, the Wilcox-Traci's two-equation model is still applied, which can be smoothly connected with the modified Cebeci's model for eddy viscosity. i All other governing equations, Wilcox-Traci's two equations, the initial and boundary conditions and the input data of Jones are referred to Cherng-Tao's paper, and are numerically solved by a finite-difference method of GENMIX computer program developed by Spalding. Finally, the distribution of viscosity parameter is obtained and it is very similar in shape to the Jone's result. Also, the predicted velocity profile in this paper is better than that of Cherng-Tao's model in comparison with Jones' experimental data. However, the discrepancies between predicted results and measured data still exist, which may be due to the assumption of the global single-step chemical reaction. Further investigation is needed to improve the prediction.