The Empirical Equations for Estimating Spanwise Loading Distribution on a Straight-Trapezoidal Wing Planform Formulated by using Data Generated from Lifting-Line Theory and Least Squares Approximation Method

Tosaporn Soontornpasatch

doi:10.55003/ETH.430204

Authors

Tosaporn Soontornpasatch Department of Mechanical and Aerospace Engineering, Faculty of Engineer, King’s Mongkut University of Technology North Bangkok, Thailand

DOI:

https://doi.org/10.55003/ETH.430204

Keywords:

Aerodynamics, Straight-Trapezoidal wing, Wingspan load distribution, Lifting-line theory

Abstract

The empirical equations for estimating a span loading distribution on a straight-trapezoidal wing planform are presented in this paper. The main concept is that the spanwise loading coefficient can be presented as a function of aspect ratio, taper ratio and spanwise position on a wingspan. The lifting-line theory is used to generate data of spanwise loading coefficient at each condition of these three parameters and the curve fitting process is applied to find the suitable equations that can represent the data. These equations can be used to determine the location of center of pressure and spanwise loading distribution on a wingspan. They can be applied in the case of a straight-trapezoidal wing planform that has no geometric and no aerodynamic twist along the spanwise direction. The flow condition is incompressible flow and the range of angle of attack is at the low to moderate which viscosity has no significant impact in the flow field. The results from the empirical equations are compared to those from Anderson’s method and experimental data. The comparison shows that the results from these empirical equations agree very well with the data from both theoretical and experimental data which the detail is discussed in this paper.

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