Effect of internal flow field and aeroacoustics of cross flow fan (CFF) with different types of inlet guide vanes (IGVs) is analyzed by experimental and numerical methods. With the base type of IGV (BA), pressure rise of CFF is increased at the same flow rate as the one without IGV (Prototype-No IGV). However, power consumption of CFF with IGV is also increased at the same flow rate. Moreover, total sound pressure level of CFF with IGV is highly increased by 9dBA and more than 15 dBA increase of SPL is also found at the first three harmonics of blade passing frequency of CFF. Internal flow field of CFF with different types of IGVs is analyzed by numerical method. Design method of IGV used in CFF is discussed based on simulated results and improved IGV (OP) is manufactured and measured. Compared with BA, OP has lower flow rate and highly decreased noise not only in total SPL but also in the first three harmonics of blade passing frequency. Compared with the prototype, OP has a little larger noise but lower power consumption benefit at the same flow rate. According to the analysis, it can be concluded that inlet flow condition of CFF is improved with suitable IGV and inlet flow separation is reduced. Benefit of large decrease of power consumption with a little increase of noise penalty of CFF can be achieved with careful design of IGV. Moreover, alteration of airfoil in CFF from single arc to more complex airfoils is convenient to design with the help of IGV.
1929 Study on Internal Flow of an Undershot Type Cross-Flow Water Turbine