期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
A Numerical Investigation on the Influence of the Circular Ring on the Aerodynamic Noise Generated by a Cooling Fan
1
作者 Jun Feng Tao Bian +1 位作者 Qianpeng Han Bing Wang 《Fluid Dynamics & Materials Processing》 EI 2023年第1期1-14,共14页
The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level(OASPL).The results demonstrate th... The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level(OASPL).The results demonstrate that when the circular rings cover near 2/3 of the width of the blade tips of the rotor in the axis direction,the rotor has the lowest OASPL and the related total pressure efficiency and flow mass rate are better than the corresponding values obtained for a reference rotor without a circular ring.With increasing the width of the circular ring in the axis direction,the tip vortex around the trailing edge of the blade tip becomes smaller and finally disappears.Meanwhile,a separated flow field arises gradually and then grows in size around the middle of the junction of the blade tips with the ring.When the circular rings cover nearly 2/3 s of the width of the blade tips of the fan in the axis direction,the extension of the separated flow around the blade’s tip attains a minimum. 展开更多
关键词 cooling fan width of the circular ring aerodynamic noise CFD simulation
下载PDF
New Design Method for Engine Cooling Fan
2
作者 黄虹宾 郑世琴 +1 位作者 刘淑艳 阎为革 《Journal of Beijing Institute of Technology》 EI CAS 1998年第4期359-365,共7页
Aim To put forward a type of math model for optimizing fan′s twisting law.Methods This math model wu based on turbo-machinery Euler equations and calculus of variation, it was conducted for optimizing the aerodynamic... Aim To put forward a type of math model for optimizing fan′s twisting law.Methods This math model wu based on turbo-machinery Euler equations and calculus of variation, it was conducted for optimizing the aerodynamic parameters along the blade height of the fan, and the math method was produced for the optimization of fan's twisting law. Results The type 6102Q engine cooling fan was optimized by use of this model, and the calculation on data were contrasted with those of iso-reaction coefficiency flow type and free vortex flow type. Some probleme existing in long blade can be solved by use of above method. Conclusion The design parameters needn't be determined artificially, so calculating results are more rational to a high degree than that from other mehods. 展开更多
关键词 cooling fan twisting law optimum design
下载PDF
Heat stress alleviation for dairy cows housed in an open-sided barn by cooling fan and perforated air ducting(PAD)system 被引量:2
3
作者 Xie Lina Wang Chaoyuan +5 位作者 Ding Luyu Gui Zhiyuan Zhang Lu Shi Zhengxiang Li Baoming Jia Chuntao 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2017年第6期1-10,共10页
Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in China.Many farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ven... Curtain-sided barns with circulation fans above stall are commonly used to house dairy cows in China.Many farms equipped with circulation fans are unable to provide appropriate cooling,especially for the naturally ventilated shed,which can result in decreasing feed intake and milk production.For alleviating heat stress and improving animal comfort,a system consisting of an air cooler and a 30 m perforated air duct(PAD)was integrated to evenly distribute cooling air.The air was cooled by underground water and delivered to targeted zones above stall bed.The system was evaluated in an open sided dairy barn in Tianjin,China.For the stalls equipped with PAD system,air velocity reached above 1.1 m/s at 0.5 m height plane of the stall space,and was more uniformly distributed.Compared to the stalls equipped with circulation fans,the PAD system lowered air temperature by 1.5℃,and increased relative humidity by 8.1%.On average,Temperature Humidity Index(THI)and Equivalent Temperature Index(ETI)were decreased by 0.5 and 0.6,respectively.After a 15 days’operation of the system,rectal temperatures of the treated dairy cows were significantly lowered.The results also showed that the cows under PADs had a higher milk production.These findings suggest the PAD can be an effective cooling alternative for naturally ventilated dairy barns to alleviate heat stress. 展开更多
关键词 dairy cow heat stress perforated air duct cooling fan naturally-ventilated barn
原文传递
Flow Fields with Tip Leakage Vortex in a Small Axial Cooling Fan 被引量:2
4
作者 Norimasa Shiomi Ying zi Jin +2 位作者 Kenji Kaneko Yoichi Kinoue T. Setoguchi 《Journal of Thermal Science》 SCIE EI CAS CSCD 2008年第2期156-162,共7页
In order to improve the fan characteristics, especially efficiency and noise level of a small axial cooling fan with a large tip clearance, the internal flow measurements with tip leakage vortex were carried out at fa... In order to improve the fan characteristics, especially efficiency and noise level of a small axial cooling fan with a large tip clearance, the internal flow measurements with tip leakage vortex were carried out at fan rotor outlet us- ing an I-type hot-wire probe. The probe was set toward two directions, parallel and normal to the meridional plane of test fan, and the two directional velocity components were measured. From the result of fan test it was found that the test fan didn't have the unstable characteristic with a positive gradient on its pressure - flow-rate curve. From the results of velocity measurement it was observed that the tip leakage vortex exited at maximum efficiency flow-rate and large flow-rate conditions. However, at small flow-rate conditions the tip leakage vortex was not observed and it was found that the flow field were enlarged toward radial outwards 展开更多
关键词 Axial fan cooling fan internal flow and tip leakage vortex
原文传递
Diagnosis and Design Improvement of the Internal Flow Field in an Automotive Cooling Fan Based on Boundary Vorticity Dynamics, Part Ⅰ: Blade Profile Scaling and Rotation
5
作者 PENG Zhigang OUYANG Hua +1 位作者 WU Yadong TIAN Jie 《Journal of Thermal Science》 SCIE EI CAS CSCD 2022年第6期2411-2423,共13页
To optimize the aerodynamic performance of the automobile cooling fan(ACF), the internal flow field of the original fan was numerically simulated. According to the theory of boundary vorticity dynamics(BVD), the distr... To optimize the aerodynamic performance of the automobile cooling fan(ACF), the internal flow field of the original fan was numerically simulated. According to the theory of boundary vorticity dynamics(BVD), the distribution laws of the boundary vorticity flux(BVF) on the blade surface and the circumferential vorticity(CV) at the wake plane of the fan were analyzed, and the underlying various negative factors, such as vortex shedding, separated flow and complicated secondary flow, on the fan blade surface and its dynamic source were diagnosed. Combined with the velocity triangle theory, the mathematical relationship between the BVF diagnosis and the geometrical characteristics of the blade profile(hereinafter referred to as profile) is used to guide the design improvement of the blade. The analysis found that at the same speed, the extension and rotation of the profile could match a smaller input torque at the same flow rate and pressure rise, thereby improving the efficiency of the fan. The test results confirmed the above conclusion. The peak efficiency of the improved fan has been increased by 2.3%, and the aerodynamic performance in the low-flow-rate has been improved. The conclusion of the study shows the applicability of the BVD theory in the diagnosis and design improvement of ACF internal flow. 展开更多
关键词 boundary vorticity flux automotive cooling fan design improvement blade profile
原文传递
Thermodynamic performance assessment of vacuum membrane-based dehumidification and air carrying energy radiant air-conditioning system(VMD-ACERS) 被引量:2
6
作者 Liang Chun Guangcai Gong +1 位作者 Xi Fang Pei Peng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第6期217-227,共11页
Temperature and humidity independent control(THIC)air-conditioning system is a promising technology.In this work,a novel temperature and humidity independent control(THIC)system is proposed,namely VMD-ACERS,which inte... Temperature and humidity independent control(THIC)air-conditioning system is a promising technology.In this work,a novel temperature and humidity independent control(THIC)system is proposed,namely VMD-ACERS,which integrates vacuum membrane-based dehumidification and air carrying energy radiant air-conditioning system.This work establishes a novel coefficient of performance(COP)model of VMD-ACERS.The main parameters affecting the COP of conventional fan coil unit cooling system(FCUCS)and VMD-ACERS are investigated.The performance of FCUCS and VMD-ACERS are compared,and the energy-saving potential of VMD-ACERS is proved.Results indicate that,for FCUCS,the importance ranking of parameters is basically stable.However,for VMD-ACERS,the importance ranking will be affected by FCU and refrigerant.The most important parameters of VMD-ACERS are condensation temperature and permeate side pressure.On the contrary,superheating,subcooling are relatively less important parameters.For VMD-ACERS,it is not necessary to pursue the membrane with very high selectivity,because the selectivity of membrane would also be a less important parameter when it reaches 500.The COP of VMD-ACERS is higher than that of FCUCS when the permeate side pressure is higher than 8 k Pa.The VMD-ACERS solves two technical problems about power-saving and thermal comfort of conventional THIC,and can extend the application of THIC air-conditioning system. 展开更多
关键词 fan coil unit cooling system Temperature and humidity independent control ACERS Vacuum membrane-based dehumidification COP
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部