The inlet/isolator is one of the important parts to the SCRAMjet engine. In the present paper, the flow fields within an inlet and isolator of a SCRAMjet engine have been simulated by the Reynolds-Averaged Navier-Stok...The inlet/isolator is one of the important parts to the SCRAMjet engine. In the present paper, the flow fields within an inlet and isolator of a SCRAMjet engine have been simulated by the Reynolds-Averaged Navier-Stokes equations with the Baldwin-Lomax algebraic turbulence model. The second order H. C. Yee TVD scheme is used for the inviscid flux terms and a central difference considering the character of flow is used for the diffusion terms. The code was used to simulate the flow field of three types of the inlet/isolator models. The results show that the configuration of the internal compression surface of the inlet and the divergent angle of the isolator have a great important effect on the characteristics of the inlet/isolator.展开更多
In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpi...In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpired solar air collector(UTC).Besides the lattice Boltzmann equation(LBE) for time evolution of particle distribution function for fluid field,we introduce an analogy,LBE for time evolution of distribution function for temperature.Both temperature fields of fluid(air) and solid(porous media) are modeled.We study the effects of fan velocity,solar radiation intensity,porosity,etc.on the thermal performance of the UTC.In general,our simulation results are in good agreement with what in literature.With the current system setting,both fan velocity and solar radiation intensity have significant effect on the thermal performance of the UTC.However,it is shown that the porosity has negligible effect on the heat collector indicating the current system setting might not be realistic.Further examinations of thermal performance in different UTC systems are ongoing.The results are expected to present in near future.展开更多
文摘The inlet/isolator is one of the important parts to the SCRAMjet engine. In the present paper, the flow fields within an inlet and isolator of a SCRAMjet engine have been simulated by the Reynolds-Averaged Navier-Stokes equations with the Baldwin-Lomax algebraic turbulence model. The second order H. C. Yee TVD scheme is used for the inviscid flux terms and a central difference considering the character of flow is used for the diffusion terms. The code was used to simulate the flow field of three types of the inlet/isolator models. The results show that the configuration of the internal compression surface of the inlet and the divergent angle of the isolator have a great important effect on the characteristics of the inlet/isolator.
基金Supported by the National Nature Science Foundation of China under Grant Nos. 10932010,11072220,11072229,U1262109,51176172,and 10972208
文摘In this letter,we present a lattice Boltzmann simulation for complex flow in a solar wall system which includes porous media flow and heat transfer,specifically for solar energy utilization through an unglazed transpired solar air collector(UTC).Besides the lattice Boltzmann equation(LBE) for time evolution of particle distribution function for fluid field,we introduce an analogy,LBE for time evolution of distribution function for temperature.Both temperature fields of fluid(air) and solid(porous media) are modeled.We study the effects of fan velocity,solar radiation intensity,porosity,etc.on the thermal performance of the UTC.In general,our simulation results are in good agreement with what in literature.With the current system setting,both fan velocity and solar radiation intensity have significant effect on the thermal performance of the UTC.However,it is shown that the porosity has negligible effect on the heat collector indicating the current system setting might not be realistic.Further examinations of thermal performance in different UTC systems are ongoing.The results are expected to present in near future.
