Theoretical and experimental supersonic lateral-directional stability characteristics

A program has been initiated at NASA Langley Research Center to assess several methods for estimation of lateral-directional stability. As a basis for comparison, experimental data are presented for a simple wing-body vertical tail configuration. The methods for estimating the characteristics include a second-order shock expansion and panel method (MISLIFT), a slender body and 'first-order' panel method (APAS), and a 'higher-order' panel method for linearized supersonic flow (PAN AIR). The results show that PAN AIR provides accurate estimates of these characteristics at moderate angles of attack for complete configurations with either single or twin vertical tails. APAS provides estimates for complete configurations at zero angle of attack. However, MISLIFT only provides estimates for the simplest body-vertical tail configurations at zero angle of attack.