Investigation On The Flow And Combustion Characteristics Of Flameholder In Nonuniform Field

The afterburning is usually placed after turbines, where the air speed is much greater than combustor. Thus a flameholder is built to create stable ignition source. Except of the concentration of gas, the performance would also depend on the downstream flow structure of flameholder. Therefore, it would be of great practice interest to grasp the characteristic of flow at downstream of flameholder under different configurations and working conditions. It would help to get deep understanding of performance of flameholder and guide us to design new flameholder. Besides, the flameholder would create resistance when the afterburner is not run. Thus, a study of its characteristic of flow resistance is also inevitable.Ununiformity of different degree is existing when the air entering afterburners. However, previous work are all carried out under uniform velocity inlet. In order to study the impact of velocity ununiformity on performance of various flameholders, three kinds(h/H=3/6 h/H=4/6 h/H=5/6) of different degree of velocity ununiformity(30%,40%,50%) are created through special designed porous broad. Numerical study were carried to predict the created flow field and cold flow and flow rate distribution were acquired which preliminary validate the research method.The experimental research mainly included total pressure loss, performance of ignition and lean blowout and combustion efficiency. The results show that the total pressure loss would increase, the fuel/air ratio decreases, the combustion efficiency increases as inlet mach number increses; Under different inlet condition, total pressure loss, performance of ignition and lean blowout and combustion efficiency has different trend which has advantage and disadvantage on flow resistance; The pilot flameholder generally has same totally pressure loss with V-model flameholder; The impact of temperature on combustion and resistance is also nonlinear and has different impact on different flameholder.What has been done would be of great reference value on afterburner design.