Research On Flame Stabilization And High-performance Combustion Of Integrated Scheme

Turbine Based Combined Cycle(TBCC)has always been extraordinarily concerned for its long-range operations and good economic efficiency.Multi-mode ramjet combustor is the critical component for TBCC,it need achieve high-efficiency combustion,which take both turbo mode and ram mode into consideration.This paper is mainly focused on flame stabilization and high-efficiency combustion,the integrated scheme is put forward including diffusion,injection,stabilization and cooling.And the performance of multi-component design is investigated through experimental method and numerical simulation.The main researches are drawn:Analyzing the combustion technical difficulties of integration design in multi-mode ramjet combustor,the experimental set-up was built,which was comprised of preheating system and measuring system to simulate wide-range aerodynamic and thermodynamic inlet conditions.And the image processing method was put forward to recognize flame boundary.Moreover,numerical simulation method was conducted and validated with high precision and low cost.Aiming at the combined research of diffusion and ignition,two central pilot burners,such as truncated cone and step,were put forward.And the flow characteristics,the performance of ignition and extinction,the development process of ignition,the flame expansion were changing with velocity,temperature,oxygen content and sudden expansion height.As presented at flow conditions of 50～200m/s、600～900K,the 80mm-height truncated pilot burner was with smallest flow resistance.Additionally,the 30mm-height step pilot burner redesigned from truncated pilot burner was with broadest envelop of ignition and extinction.The combustion performance of integrated bluff body,including injection,stabilization and cooling,was investigated.As to V-type bluff body,the influence of aerodynamic and structural parameters on flame expansion was carried out in premixed conditions.And the bluff body was close coupled with injection,then the influences of aerodynamic and structural parameters on fuel distribution and flame structure were obtained using high speed camera,additionally,the flame images were processed through enhanced flame image processing method.Based on the close coupled scheme,a new cooling structure was put forward to protect flame holder from ablation.And the influence of cooling air mass rate on flow pattern,flame structure and wall temperature distribution was mastered.To strengthen fuel injection and accelerate flame propagation in high velocity and temperature,an integrated stabilizer with spheno-lugs and an integrated stabilizer with triangle-lugs were put forward,which were conducted to find out the change of flow pattern,fuel distribution,flame structure and outlet temperature.It was on premise that the flow resistance was increasing slightly,the flame expansion rate of spheno-lugs was 5.2%-29.4% improved,and the 1000mm-downstream temperature of triangle-lugs was 41 K greater than no-lugs.At flow conditions of 50～200m/s、600～900K,the of flow characteristics and combustion performance of central pilot burner matching with strut stabilizer were investigate to optimize structural parameters,which consisted of flow characteristics,the performance of ignition and extinction,ignition development process.As presented,the pilot burner matching with 30mm-width and 30°-backward bluff body was with the lower flow resistance,the broader envelop of ignition and extinction,the faster flame propagation rate.In summary,the study of integration design in multi-mode ramjet combustor provided technological support for achieving low-resistance and high-efficiency combustion.