在布套式空调装置中,布风道系统阻力的大小直接影响到装置的噪声及电耗,因此布的选择是布套式空调装置设计中的关键问题。由浙江省上虞风机厂试制的 BK 型布套式空调装置,于八三年四月首次在上海市川沙县食品公司试用,同年七月由中国食...在布套式空调装置中,布风道系统阻力的大小直接影响到装置的噪声及电耗,因此布的选择是布套式空调装置设计中的关键问题。由浙江省上虞风机厂试制的 BK 型布套式空调装置,于八三年四月首次在上海市川沙县食品公司试用,同年七月由中国食品公司通过鉴定。在设计中该厂与上海市食品公司先后在有关纺织品,从几百种布中挑选了十一种不同透气性能的布,其中包括五种规格型号的布、尼龙、丝织等,分别在上虞风机厂气动性能试验室进行局部阻力系数与表面喷风口风速的测试。展开更多
The wall surface roughness renders a significant impact on ventilation of roadways and cross-sectional wind speed distribution.Herein,the wall roughness(Ra)in the roadway has been defined theoretically.Moreover,three-...The wall surface roughness renders a significant impact on ventilation of roadways and cross-sectional wind speed distribution.Herein,the wall roughness(Ra)in the roadway has been defined theoretically.Moreover,three-center arched roadway models for different situations are established based on the normal distribution of roof roughness.The influence of inlet velocity,roof roughness and roadway height on wind speed distribution is systematically studied by using Fluent software.At Ra=0.1 m,the simulation results reveal that the wind speed is negatively related to the distance from the wall to the point where 80%of the central wind speed is reached(DA).Also,the wind speed distribution is significantly influenced by increasing the roof roughness.However,the wind speed distribution becomes asymmetric at Ra=0.2 m and 0.3 m.Furthermore,the low-speed area(v≤1 m/s)started to concentrate on the roof with the increase of roadway height.Overall,an Ra value of<0.1 m can reduce the influence of wall roughness on wind speed distribution of the roadway,which is suggested in practical applications.展开更多
In recent years, there has been a rapid development of the wind farms in Japan. It becomes very important to investigate the wind turbine arrangement in wind farm, in order that the wake of one wind turbine does not t...In recent years, there has been a rapid development of the wind farms in Japan. It becomes very important to investigate the wind turbine arrangement in wind farm, in order that the wake of one wind turbine does not to interfere with the flow in other wind turbines. In such a case, in order to achieve the highest possible efficiency from the wind, and to install as many as possible wind turbines within a limited area, it becomes a necessity to study the mutual interference of the wake developed by wind turbines. However, there is no report related to the effect of the turbulence intensity of the external flow on the wake behind a wind turbine generated in the wind tunnel. In this paper, the measurement results of the averaged wind profile and turbulence intensity profile in the wake in the wind tunnel are shown when the turbulence intensity of the external wind was changed. The wind tunnel experiment is performed with 500mm-diameter two-bladed horizontal axis wind turbine and the wind velocity in wake is measured by an I-type hot wire probe. As a result, it is clarified that high turbulence intensities enable to the entrainment of the main flow and the wake and to recover quickly the velocity in the wake.展开更多
文摘在布套式空调装置中,布风道系统阻力的大小直接影响到装置的噪声及电耗,因此布的选择是布套式空调装置设计中的关键问题。由浙江省上虞风机厂试制的 BK 型布套式空调装置,于八三年四月首次在上海市川沙县食品公司试用,同年七月由中国食品公司通过鉴定。在设计中该厂与上海市食品公司先后在有关纺织品,从几百种布中挑选了十一种不同透气性能的布,其中包括五种规格型号的布、尼龙、丝织等,分别在上虞风机厂气动性能试验室进行局部阻力系数与表面喷风口风速的测试。
基金Project(2017YFC0602901)supported by the National Key Research and Development Program of ChinaProject(2019zzts988)supported by the Postgraduate Independent Exploration and Innovative Project of Central South University,China。
文摘The wall surface roughness renders a significant impact on ventilation of roadways and cross-sectional wind speed distribution.Herein,the wall roughness(Ra)in the roadway has been defined theoretically.Moreover,three-center arched roadway models for different situations are established based on the normal distribution of roof roughness.The influence of inlet velocity,roof roughness and roadway height on wind speed distribution is systematically studied by using Fluent software.At Ra=0.1 m,the simulation results reveal that the wind speed is negatively related to the distance from the wall to the point where 80%of the central wind speed is reached(DA).Also,the wind speed distribution is significantly influenced by increasing the roof roughness.However,the wind speed distribution becomes asymmetric at Ra=0.2 m and 0.3 m.Furthermore,the low-speed area(v≤1 m/s)started to concentrate on the roof with the increase of roadway height.Overall,an Ra value of<0.1 m can reduce the influence of wall roughness on wind speed distribution of the roadway,which is suggested in practical applications.
基金A part of this study is funded by METI/NEDO in Research and Development Project of Next Generation Wind Turbine Generation Technology (R&D of Basic and Applied Technology)
文摘In recent years, there has been a rapid development of the wind farms in Japan. It becomes very important to investigate the wind turbine arrangement in wind farm, in order that the wake of one wind turbine does not to interfere with the flow in other wind turbines. In such a case, in order to achieve the highest possible efficiency from the wind, and to install as many as possible wind turbines within a limited area, it becomes a necessity to study the mutual interference of the wake developed by wind turbines. However, there is no report related to the effect of the turbulence intensity of the external flow on the wake behind a wind turbine generated in the wind tunnel. In this paper, the measurement results of the averaged wind profile and turbulence intensity profile in the wake in the wind tunnel are shown when the turbulence intensity of the external wind was changed. The wind tunnel experiment is performed with 500mm-diameter two-bladed horizontal axis wind turbine and the wind velocity in wake is measured by an I-type hot wire probe. As a result, it is clarified that high turbulence intensities enable to the entrainment of the main flow and the wake and to recover quickly the velocity in the wake.
