Vortex lattice methods are particularly appealing for design optimization because of their simplicity and because they capture the essence of the ow eld over the wings and control surfaces of an aircraft. They can produce reasonably accurate estimates for the lift distribution, induced drag, and the moments for a given planform. The main limitations however, are the inability of these methods to estimate viscous drag and the lack of any modeling of nonlifting surfaces (e.g. fuselage and appendages). The focus of this paper is to evaluate the success of several approaches that have been taken for including the e ects of nonlifting surfaces in vortex lattice analysis. Two vortex lattice codes will be examined to determine their success at including these interference e ects. The level of accuracy of the codes when body objects, such as the fuselage, are modeled in addition to the lifting surfaces will be examined and compared to experimental data. Finally, the use of lattice codes in the aircraft design process and the appropriate design stage for their use will be discussed.

Modeling Fuselage Aerodynamic Effects in Aircraft Design Optimization

The National Aerospace Laboratories (NAL's) panel code capability buildup has been highlighted and several interesting applications are discussed to bring out the utility of panel methods in aerospace research and development.

https://nal-ir.nal.res.in/3173/1/pages-211-233.pdf

Panel codes for aerodynamic analysis at NAL

The panel code NALSOF0509 (available in the SOFFTS library13; at NAL) can compute the chordwise and spanwise load distributions, centre of pressure locations on the wing, shift of the aerodynamic centre due to the fuselage and overall aerodynamic coefficients. This code is presently used to generate data on the aircraft configurations like NALLA and LTA, and for the delta wing-body tested in the 1ft.x1ft. tunnel of the Experimental Aerodynamics Division. The code is also validated against the tunnel results available for AGARD-B model. This report describes in brief some of these experience.

Application of a panel code for in house aircraft projects: Part I

The code NALSOP0509, available in the SOFFTS Library of NAL
has been extended to include a design of wing-body combinations to, minimize induced drag for specified lift and pitching moments at sub- or super--sonic flow conditions, Method of Lagrangean multiple is used to obtain the optimum camber and twist distributions for the wing in the presence of a body. SOFFTS Library of NAL has now been updated with this version of the code.

R Rangarajan

Papers

Panel codes for aerodynamic analysis at NAL

Extension to the Panel Code NALSOP0509 to Include Designof Wing-Body Configurations for Minimum Induced Drag at given lift and pitching moment