Large eddy simulation of small hole jet flow inside swirl channel of gas turbine
1. Institute for Energy Research, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2. School of Energy and Power Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China
Abstract:To solve the problem of smallhole fuel jet flow in PRECCINSTA gas turbine, the large eddy simulation (LES) method was used to simulate the mixing process of methane and air in cold isothermal state by the flow field calculation program of LESOCC2C. Four simulations were performed with global equivalent ratio of 0.70,0.83 and with grid combination of 1.2 million or 1.8 million cells, respectively. The results show that because of the short mixing time, there is large equivalent ratio fluctuation when the mixture enters combustion chamber, resulting in strong partially premixed combustion phenomenon in combustion chamber. For the global equivalent ratio of 0.83, the calculated equivalent ratio fluctuation range is close to [0.59, 1.15]. For the global equivalent ratio of 0.70, the equivalent ratio fluctuation range is [0.40, 1.00], which is beyond the applicable range of partial reaction mechanism. Therefore, suitable combustion model and simplified reaction mechanism are required to conduct the LES of PRECCINSTA combustion problems with small hole fuel jet flow phenomenon.