Experimental Investigation on Liner Cooling Characteristics of a Mixed-Flow Trapped Vortex Combustor

The mixed-flow trapped vortex combustor(TVC)is a new type of combustor that applies trapped vortex flame stabilization technology to mixed-flow combustor.Compared with the traditional mixed-flow combustor,the mixed-flow TVC has many advantages,such as complicated structure of the vortex flow field inside liner,large cooling area,significant local hot spots on the liner,and large wall temperature gradient.In this paper,for a mixed-flow TVC with inclined multi-hole cooling,the liner wall temperature of an annular test rig was examined in experiments.The effects of inlet temperature(T3),inlet Mach number(Ma)and fuel to air ratio(FAR)on the temperature of liner wall were obtained,which provided a valuable reference for understanding the distribution characteristics of liner wall temperature.The experiment results show that the highest temperature is found to be on the fore-wall of the cavity.When T3 and FAR are low,the highest wall temperature was obtained in injector plane.However,the wall temperature in the center plane between two adjacent injectors was higher than that in injector plane under the condition of high FAR and T3.With the increase of FAR and T3,the average wall temperature increases.Ma has a slight impact on the average wall temperature.In addition,this paper provides an effective reference for the design and improvement of the liner cooling structure of the combustor with many discontinuous small-area walls in the flow direction.It is difficult to form a continuous film,and cooling requirements can’t be achieved only by using inclined multi-hole cooling structure.Consideration needs to be given to other efficient cooling structures,or to the combination of multiple cooling structures.