Study On Characteristics Of Wind Field In Ground Layer On Hilly Terrain

When air flows over the mountainous region, the complex terrain features and physiognomy will observably change the wind speed, wind pressure and turbulence characteristic of boundary-layer flow, and make the wind field in these areas much different from that in flat areas, resulting in the distribution of the wind speed and wind pressure are irregular. Therefore, studying the distribution features of the wind field in mountainous region and the changed regulations of the wind field resulting from the hill slope, height and the inflow wind speed, which is of great significance for us in choosing appropriate sites for buildings in mountainous region and in wind-resistant design.In this article the features of simple (a single mountain) and complex (several continuous mountain) wind field in ground layer are studied respectively and systematically by the means of combination of wind tunnel tests and numerical simulation. The study items are carried out as follows:â‘ The typical wind field of a single mountain is analyzed by wind tunnel tests of the rigid mountain model. The affection to the characteristics of average wind speed and fluctuating wind speed rms on different sites of the surface in the mountain by different mountain slopes, heights and the inflow wind speed is discussed systematically;â‘¡By using numerical simulation based on computation fluid dynamics, the wind field of a single mountain is calculated and analyzed, then, the affection to the characteristics of average wind speed on different sites of the surface in the mountain by different mountain slopes, heights and the inflow wind speed is verified. It can be concluded that the model of numerical simulation is accurate and reliable through Numerical simulation results comparison with experimental simulation result.â‘¢According to the results of wind tunnel tests and numerical simulation for a single mountain, three-dimensional models of several continuous mountains are established and numerical simulation is carried out, the affection to the characteristics of average wind speed on different sites of the surface in the disturbed mountain resulting from different slopes and heights of the block mountain is discussed respectively if there is a block mountain in the direction of inflow, the affection to the characteristics of average wind speed on different sites of the surface in the disturbed mountain resulting from the number of continuous mountains if there are several block mountains is discussed.â‘£On the basis of summarizing the distribution features of wind field in different terrains area mentioned before, some suggestions on choosing sites for buildings near a single mountain and several continuous mountains are proposed respectively from the perspective of avoiding wind disaster and getting suitability.