Experimental investigation of dynamic ground boundary condition for a non-slender delta wing


Koçak G., YAVUZ M. M.

CEAS Aeronautical Journal, 2024 (Scopus) identifier

  • Publication Type: Article / Article
  • Publication Date: 2024
  • Doi Number: 10.1007/s13272-024-00744-8
  • Journal Name: CEAS Aeronautical Journal
  • Journal Indexes: Scopus, Compendex
  • Keywords: Aerodynamic coefficients, Ground effect, Height stability, Leading-edge vortex, Longitudinal static stability, Non-slender delta wing, Stall, Three-dimensional surface separation
  • Middle East Technical University Affiliated: Yes

Abstract

In this paper, the ground boundary condition was studied for static ground effect (SGE) of a non-slender delta wing with sweep angle of 45 degree in a low-speed wind tunnel at Reynolds number of 9x104 considering static ground condition with a fixed flat plate and dynamic ground condition with a moving belt mechanism. The static ground condition was further simulated with the Belt Off condition, where the tunnel floor represented the ground, hence static ground effect was demonstrated with three different fidelity levels. The characterization of different ground boundary conditions was accomplished using force measurements considering the aerodynamics and the longitudinal static stability of the wing. The results indicate that dynamic ground condition results in larger area under the lift-to-drag ratio versus angle of attack curve compared to out of ground cases rather than increased peak values observed for the static ground condition. Belt On and Belt Off cases resulted in reduced slopes for the aerodynamic coefficients compared to the static ground condition, which resulted in different aerodynamic center positions on longitudinal axis. Dynamic pressure loss and flow angularity changes due to the ground boundary condition might be the driving mechanisms for the altered stability characteristics.