Modeling of Gas Turbine Combustion Chamber; By Using Network Method

This paper deals with utilization of the network method to fast analysis of the gas turbine combustors. In this method, a combustor is divided into several independent flows by some nodes and interconnecting elements. The fundamental equations which should be satisfied in the network method are conservation equations of mass and energy at each node and the pressure drop-flow rate correlation for each element. These equations constitute a system of equations of flow rate and pressure drop. Solving this system using a set of initial value gives pressure, flow rate, and density at each node that finally leads to a converging solution. The conventional relations for pipes and orifices are used for flow modeling. In order to combustion modeling, equilibrium assumption is applied in the primary and secondary combustion zones. The dilution effect is considered by entering the air from dilution holes into the flow of combustion products. The liner temperature is calculated by considering the effects of convection and radiation in the combustor. By the network method in a can type combustor, at the first step a cold flow analysis is performed and the flow rate and the pressure drop in each element are obtained. In the next step by including the combustion of kerosene and heat transfer, the distribution of flow rates, pressure, temperature, and species concentration of combustion products are calculated. The computation results are compared with the existing experimental data and an excellent agreement is seen. The quality of results and the solution procedure of the problem show that the network method is able to present a costly and accurate analysis to help the combustor designers