Numerical Investigation On Rotating Detonation Combustion Chamber Of Self-priming

Rotating detonation engines (RDEs) have gained much worldwide interest lately. Such engines have huge potential benefits arising from their simplicity of design and manufacture,lack of moving parts and high rate of energy conversion that may be even more superior than other detonation engines. However, research work to date has focused almost exclusively on RDEs as aerospace propulsion. The self-priming RDE which integrated with land-based or marine power turbomachinery is presented in this thesis.Based on FLUENT software, the inlet mass flow rate is adaptively adjusted according to the different flow state, and the inlet boundary conditions are achieved by UDF, on the strength of one-step reaction, without consideration of the effect of viscosity, heat transmission and diffusion on flow, mixtures of hydrogen/air are used to simulate RDE flow field. By the numerical simulation of two-dimension simplified model. The flow field and the structure of rotating detonation wave in the combustion chamber are analyzed in detail. The effects of combustion chamber diameter on detonation process and detonation combustion performance are also discussed. The initiation of detonation waves, the flow field and the detonation combustion performance under the condition of rich and lean burn off are investigated by changing the excess air coefficient of n. Three-dimension RDE flow field is simulated, the combustion chamber flow field characteristics of axial cross section and radial section is analyzed, the effect of internal and external wall convergence divergence on combustor flow field is also expounded in this paper.The results show that there exists a critical diameter for the RDE which it can initiate successful, and it could not get a stable rotating detonation wave if the circumference of combustion chamber is less than the critical diameter; under the same axial length, with the increasing of combustion chamber diameter, the detonation wave propagation speed gradually accelerated,mass flow rate of burning gas is greater,and the effect of supercharging is more obvious. Within the calculation range in this paper, when n is equal 0.2 or 5.0, the rich and lean burn off was occurred respectively. When n is in the stoichiometric equivalence ratio condition of 1, the intensity of detonation combustion is largest, and the pressure and temperature of detonation wave is highest, the maximum pressure ratio of the combustion chamber is also achieved, and the maximum detonation wave propagation velocity is founded when the n is less than 1. The inlet mass flow rate of combustion chamber increases gradually with the increasing of the value of n. For the three-dimension model, the external wall has the effect on strengthening the detonation wave,it makes the detonation wave pressure,temperature and detonation wave propagation velocity values on the external wall greater than the internal and the middle walls.On the whole, the feasibility has been proven that the rotating detonation can be used to the land-based or the marine engine based on the results in this thesis. The effect of the geometric dimensioning and the excess air coefficient on the combustion chamber performance are investigated and discussed. The conclusion in this thesis can provide the certain theoretical basis for the design of subsequent detonation combustion chamber.