Abstract
Data center has been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High power cooling fans are used for servers in the data center and there is a strong demand to increase power of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of the high power cooling fans. It is important to clarify complicated internal flow condition and influence of a geometric shape of the cooling fans on performance and internal flow condition to achieve the high performance cooling fans. Numerical analysis of a cooling fan with 40 mm square was conducted and influence of tip clearance on performance was investigated experimentally in this research.
