Research on Green Transformation of Campus Sponge and Energy Saving Facilities on Sloping Land

Based on the renovation of sponge and energy-saving facilities in a middle school in Nanning, this paper systematically studies the overall elevation of the campus, the composition of the drainage system and the layout of space functions, and formulates a characteristic scheme for the renovation of sponge and energy-saving facilities according to the characteristics of the sloping campus. In order to control the total amount of rainwater runoff, the sponge transformation mainly adopts the transformation methods of partition catchment, upper storage and lower use, multi-stage detection and classification treatment. For the purpose of solar energy and wind energy utilization, solar photovoltaic panels and small-scale wind power generation system are adopted. The application effects of sponge and energy-saving facilities are estimated and evaluated.

Comparison of Various Pressure Based Boundary Conditions for Three-Dimensional Subsonic DSMC Simulation

Three-dimensional (3D) direct simulation Monte Carlo (DSMC) has been used to simulate flow in a straight microchannel using an in-house parallelized code. In the present work, a comparative study of seven boundary conditions is carried out with respect to time required for achieving steady-state, accuracy in predicting the specified pressure at the boundaries, and the total simulation time required for attaining a statistical error within one percent. The effect of changing the Knudsen number, pressure ratio (PR), and cross aspect ratio (CAR) on these parameters is also studied. The presence of a boundary is seen to affect the simulated pressure in a cell when compared to the specified pressure, the difference being highest for corner cells and least for cells away from walls. All boundary conditions tested work well at the inlet boundary; however, similar results are not obtained at the outlet boundary. For the same cell size, the schemes that employ first- and second-order corrections lead to a smaller pressure difference compared to schemes applying no corrections. The best predictions can be obtained by using first-order corrections with finer cell size close to the boundary. For most of the simulated cases, the boundary condition employing the characteristic scheme with nonequilibrium effect leads to the minimum simulation time. Considering the nonequilibrium effect, prediction of inlet and outlet pressures and the speed of simulation, the characteristic scheme with nonequilibrium effect performs better than all the other schemes, at least over the range of parameters investigated herein.