Model support system interfrenceon zero-lift drag at trasonic speeds AIAA - 78-809

In this paper the support system interference on the zero lift drag of an axisymmetric and an aircraft type models is discussed. Two different techniques evaluate the support sting interference. It is found from these tests that the result in a reduction in the zero lift drag of as much as 20 to 50 precent of the true value. This apparent reduction in drag is found to be a strong function of unity Detailed pressure measurements over the aft-body of the axisymmetric model suggests that due to the positive pressure field imposed by the sting over the best tail region of the model the free stream Rach number at which the shocks appear in the boat-tail region will be higher when the sting is present than that without it. This will result in an increased drag divergence Mach number for the model in the presence of the sting. It is argued that because of this reason the sting effect on zero-lift drag strongly depends on the Mach number close to unity