This paper concerns with the problem on aerodynamic loadings over kinked planform wings, when lifting surface theories are used. In using “conventional” mode methods, kinked edges of the planform should be rounded in some way. The effects of roundings on loadings are investigated through BIS-QS, which is a discrete method developed in our laboratory. Another discrete method, DLM, is also used supplementarily, the results of which are shown in the appendix. Two kinds of roundings are used. It is found that the influence of roundings remains spanwise considerably far from the rounded region. Therefore it may be said that “conventional” mode methods are less efficient than discrete methods, for investigating kinked planform wings. “Modified” aerodynamic loading ΔC
p mod is introduced, to be kept free from the conventional square-root edge-singularities. It is noteworthy that quasi-conical distributions of ΔC
p mod appear near kinks. Thus the well-known peculiar loadings of swept-back, or -forward wings can be explained essentially and naturally. This quasi-conical ΔC
pmod would serve for rapid convergence of mode methods in lifting surface theory.
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