Research On Heat Transfer Characteristics Of Pulse Detonation Engine Wall

Pulse detonation engine(PDE),a new propulsion system,has become a hot research topic with its high thermal cycle efficiency,simple structure and other excellent characteristics.In the process of multi-cycle operation of PDE,the temperature of the combustion chamber wall increases continuously,which becomes an important factor restricting its application.In recent years,tube heat transfer has gradually become an important issue in PDE engineering research.To explore the heat-transfer characteristics of combustion chamber tube of PDE,the interior flow field of PDE and coupled heat-transfer process on combustion chamber wall were calculated by the CE/SE method and the finite difference method.To verify the relevant numerical results,the relevant experimental platform was built and the temperature of the combustion chamber wall was measured by the fast response thermocouple.The main contents are as follows:(1)The axisymmetric non-viscous or viscous gas-liquid two-phase detonation theory model considering wall heat transfer was established respectively.The interior flow field corresponding to the model of pulse detonation engine was calculated by the relevant CE/SE method,and the variation law of the flow field in the combustion chamber was analyzed.(2)The heat conduction model of the axisymmetric tube was established,and the heat conduction equation was solved discretely by the finite difference method.The coupled heat transfer process between the interior flow field and the wall of the combustion chamber was realized by the energy balance method.Then the heat-transfer characteristics of combustion chamber tube in a single detonation process were analyzed.And the changes in the heat transfer process of the tube were analyzed while considering the viscous action in the flow field.(3)By periodically changing the boundary condition of the thrust wall,the numerical simulation of the heat transfer in the wall of the combustion chamber under multi-cycle operation of PDE was successfully realized.Based on the analysis of multi-cycle heat transfer characteristics,the impacts of various factors on the heat transfer process of the tube wall were studied.(4)The experiment on temperature measurement of combustion chamber outer wall of PDE was carried out,and the reliability of numerical research was verified by analyzingthe relevant experimental results.It was further confirmed that the temperature of the combustion chamber outer wall rises slowly at the beginning,then gradually accelerates,and starts to rise linearly from a certain moment.Inside,the wall temperature increases linearly with the increase of the detonation frequency.And under the same structure,the closer to the thrust wall,the lower the wall temperature is.The research results in this paper reveal the heat transfer mechanism and the law of the combustion chamber wall during the operation of PDE,which is of great significance to the further study on heat transfer,thermal erosion and thermal protection of the combustion chamber wall of PDE.