Mahdi Karami - PhD candidate, Iran University of Science and Technology,
Fata Mohammadi Fard - MSc, Aerospace Engineering
Akbar Andalib - Instructor, Imam Hossein university
Mohammad Reza Heidari۴ - Associate professor, Islamic Azad university, garmsar branch

Present study is conducted to find the best equivalent nozzle for designing process of a hypersonic wind tunnel. The equivalent nozzle is appropriate for the cases that the real nozzle has not been calculated and downstream parts designers (such as test section and diffuser designers) need a reasonable upstream flow condition for their calculations. Inlet boundary condition of each case has been specified by User-Defined Function. The process of UDF specification is time-consuming and is based on a try and error method. Several cases of equivalent nozzles have been designed and examined. Comparing the results with the real nozzle data, the case of 1.2 m-length ogive curve with 0.5 degree initial angle has been selected as the best equivalent nozzle

Hypersonic Flow, Wind Tunnel Design, Nozzle Curve Calculations, Equivalent Nozzle, UDF,CFD