One dimensional network model for a reverse flow combustor

In this study, a one-dimensional empirical network code was developed for the preliminary design of a reverse flow combustor, which was intended to be used in a 1000 hp turbo-shaft helicopter engine. Network code is able to predict critical design features such as discharge coefficients at each hole set, mass flow rate distributions across the swirler, cooling devices and dilution holes, overall pressure drop across the combustor, liner wall and gas temperatures along the combustor and pollutant emissions at the exit of the combustor. By these means, many design alternatives can be scanned rapidly in early stages of design. Results are presented for a particular combustor geometry operating at idle, cruise and take-off conditions based on the cycle analysis of a turbo-shaft engine design which is intended for light duty helicopter missions. Calculated flow distributions and discharge coefficients were compared with isothermal numerical simulations and reasonably good agreement was achieved for the non-reacting case. On the other hand, liner temperatures for three operating conditions obtained from the network code were examined to see whether the liner temperatures were suitable for liner material and the obtained results showed that this particular design raises doubts when viewed from the predicted high liner temperatures.