平面L形低矮房屋平均风压分布特性数值模拟

摘要

Based on atmospheric boundary layer theory and hydrodynamic theory,numerical study was conducted on mean wind pressure distribution characteristic of plan L-shaped low-rise buildings by using FLUENT.By contrast,the simulation results agreed well with that of wind tunnel tests,which showed that the numerical simulation was reliable in numerical analyzing.Based on numerical simulation,the influence on the regularities of mean wind pressure coefficient distribution and shape factor was carried out.The parameters included wind direction,roof pitch,lengths of wing,cave height and roof shape.The results show that wind direction and roof pitch are the main factors that influence on the distribution of mean wind pressure coefficient of roof and shape factor.The site of the worst negative peak pressure changes along with wind direction.But it tends to be formed on ridge and cave of windward roof.The worst negative peak pressure of windward roof decreases with the increase of roof pitch.The distribution of mean wind pressure coefficient of roof under the leeward area is uniform.Hip roof has more positive ridges and tends to form high negative pressure zone on leeward of positive ridges.Hence,these zones are easier to be destroyed.%基于大气边界层基本理论和流体动力学基本原理,采用FLUENT软件对平面L形低矮房屋风压分布特性进行了数值模拟研究.将数值计算结果与风洞试验结果对比分析,结果吻合良好,表明数值模拟方法是合理可行的.通过数值模拟,详细分析了风向角、屋面坡度、房屋翼长、檐口高度和屋面形式等参数对平面L形低矮房屋外表面平均风压系数分布规律及体型系数的影响.结果表明:风向角与屋面坡度是影响屋面的风压系数分布与体型系数的最主要因素;最不利负压的位置随风向角的改变而不断变化,但往往出现在迎风屋面屋脊及屋檐区域;迎风屋面最不利负压随屋面坡度的增加逐渐减小,背风屋面风压系数分布相对均匀;四坡屋面阳屋脊较多,其背风区往往形成高负压区,这些区域更容易遭受风灾破坏.