Author(s)

Tang Jiyong, He Xiaoming

Corresponding Author

Tang Jiyong

ABSTRACT

In order to study factors that influences the dump diffuser performance, numerical simulation of flow structure is performed in a 3D single-dome combustor with a dump diffuser. Realizable k-ε model is chosen for the simulation with the same inlet condition for the diffuser under different dump gaps and flow splits. The numerical results show a great correspondence with experimental pressure results and PIV measurements. Based on this the numerical solution can be used to analyze the influence of flow split and dump gaps on dump diffuser performance. The results show that small dump gaps increase the static pressure recovery of the pre-diffuser and decrease its total pressure loss. The total pressure loss coefficient of the combustors reaches a minimum at a certain relative dump gap, which is around 1.7 when mass-flow split between outer and inner annuli is 1.73.

KEYWORDS

Dump diffuser, dump gap, numerical simulation