燃烧室空气流量分配试验方法模拟分析与优化

为了明确当前燃烧室流量分配试验采用的堵孔法的合理性,按照某单管燃烧室流量分配试验的实际流程进行数值模拟,分析了试验本身存在的方法误差和根源,据此提出了采用堵孔法和单侧积累式堵孔法相结合的优化试验方法,并进行了数值模拟验证。结果表明:采用堵孔法进行流量分配的测定存在一定的方法误差,该方法对火焰筒头部的测定影响较小,而对主燃孔、掺混孔和气膜冷却孔的测定影响相对较大,主要原因在于未同时考虑被测孔排及其下游孔排的过流条件;采用堵孔法和单侧积累式堵孔法相结合的方式进行流量分配测量,能够大幅度降火焰筒上主燃孔、掺混孔和气膜冷却孔的测量误差,降低幅度分别达到约6%、12%和9%,效果明显;试验方法优化前后,火焰筒上各孔排进出口截面的静压差的改变是试验方法误差一直存在的根本原因,但方法优化后这个压差的变化量及对测量结果的影响较优化前都更小。 

Simulation analysis and optimization on test method of combustor airflow distribution

In order to specify the rationality of the method of blocked holes in the current combustor flow distribution test, the numerical simulation was conducted according to the actual test procedure of a can combustor flow distribution, the test method error and the root of the generation were analyzed, the optimizational test method of associating blocked holes and accumulated blocked holes of single side was proposed, and the validation was carried out by numerical simulation. Results indicated that there were definite method errors in the flow distribution test using blocked holes method, the effects of this method on the measurement error of primary holes, dilution holes and film cooling holes on the liner were greater, while the effect on dome measurement error was smaller; the simultaneous neglect of passing flow condition of tested holes and downstream holes was the main reason; the measurement error can be reduced significantly by associating blocked holes and accumulated blocked holes of single side for the flow distribution measurement of primary holes, dilution holes and film cooling holes, which can be reduced by about 6%, 12% and 9%, showing definite improvements; There was method error before and after the test method was optimized, the static pressure difference of import and export sections of each holes on the liner changed when some holes were blocked, which was the primary cause for the existing method error, but the variation of the static pressure difference and its influence on the measurement results were smaller after the test method was optimized.