（同济大学土木工程防灾国家重点实验室，上海 200092）

[摘要]  Jensen数（屋面高度h与地面粗糙度长度z₀之比）对低矮建筑屋面和墙面风压有较大影响。基于同济大学浦东实测基地的某低矮建筑，建立了风洞试验和数值模拟模型，通过改变模型尺寸和地面粗糙度长度，用风洞试验和数值模拟方法详细研究了Jensen数对低矮建筑屋面和墙面风压的影响。结果发现对于30°坡角低矮房屋正面迎风时：迎风墙面上正风压基本与Jensen数无关；背风墙面和背风屋面上的负风压随着Jensen数的增大而增大；迎风屋面上檐口处负风压随着Jensen数的增大而增大，中间及靠近屋脊处的正风压随着Jensen数的增大而减小。这些结论对低矮房屋风洞试验和数值模拟都有一定的参考价值。

[关键词]  Jensen数；低矮房屋；风荷载；风洞试验；数值模拟

中图分类号：TU312.1

Experimental study and numerical simulation of the Jensen Number on

wind loads of low-rise buildings

Zheng Jianjian, Huang Peng, Gu Ming

(State Key Laboratory of Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China)

Abstract: The Jensen Number, defined as the ratio of building model height to aerodynamic roughness length, has great impact on wind loads of low-rise buildings’ roofs and walls. Based on a full-scale low-rise building in the field laboratory of Tongji University near Shanghai Pudong International Airport by the East China Sea, the methods of wind tunnel test and numerical simulation are employed, with modifying and adjusting the model sizes and aerodynamic roughness lengths, to study the Jensen Number effects on wind loads of roofs and walls of a low-rise building with a 30° pitch gable roof. When the wind blows normally to the building, the results show that: 1) the Jensen Number has little effects on positive shape coefficients of wind load of windward wall; 2)The absolute values of the negative shape coefficients of wind load of leeward wall and roof increase with the rising Jensen Number; 3) As the Jensen Number rises, the absolute values of negative shape coefficients of wind load of the eave of the windward roof increases, while the positive shape coefficients of wind load in the middle of windward roof or near the ridge drop with the growing Jensen Number. These results offer some academic significance to wind tunnel tests and numerical simulations of low-rise buildings.

Keywords: the Jensen Number; low-rise building; wind load; wind tunnel test; numerical simulation

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