| Stirling engines are external combustion engines, which means no combustion takes place inside the engine and there's no need for intake or exhaust valves. As the result, Stirling engines are smooth-running and exceptionally quiet. As the engine for sub, it should working with some special case, and, most important it should working without air. And Stirling engine meet it.711 Research Institute improves on Stirling engine combustor. The external combustion chamber is very important for the capability of Stirling engine, and also is an important part of the design of Stirling. But measure in combustor is difficult and costly. With the development of computer technology and modern Computational Fluid Dynamic (CFD), numerical simulation of combustor is taking more and more important role on combustor design and research.In this thesis, using the professional CFD software——Fluent, studies on methodology of combustion simulation are done. And a numerical simulation is implemented on combustor and key components of external combustion system of Stirling engine. In this thesis, summarize the experiment and theory study on the spray characteristics, introduce the CFD, and establish the spray model and the combustion model, and gain the optimal simulation results: the diameters of fuel droplets are influenced by flow rate and pray pressure; Establish the numerical model of External-Combustion Stirling engine, using the diesel or hydrogen as fuel, controlling the distributing of temperature by controlled the spray; the contours of CO2/H2O are effecting the temperature; the stirling engine with single tail pipe need optimizing its flow field; H2 is more efficiency fuel, but it need using CGR. And at last, we can get that configuration, spray, flow field, convective heat are all have effect for the temperature field of stirling engine, and also prove that this work can be useful for designing Stirling engine. |
