2-VARIABLE METHOD FOR BLOCKAGE WALL INTERFERENCE IN A CIRCULAR TUNNEL

A two-variable method for the blockage interference assessment in a ci rcular tunnel has been developed. The Prandtl-Glauert equation is appl ied to describe the subsonic flowfield. Analytical solutions are obtai ned using Fourier transform technique, by either assuming a given body of revolution profile or representing the body of revolution by a sou rce-sink distribution. Numerical examples computed by a small perturba tion inviscid code TSFOIL and a panel method code PMARC are utilized t o validate the developed two-variable method for open jet and closed c ircular tunnels. Good agreement has been found on interference pressur e coefficient assessment between the solutions of the two-variable met hod and inviscid code predictions. Results have demonstrated that the two-variable method for circular tunnel blockage wall interference is ready for experimental verification.