Year: 2024
Type: article
Abstract: The aim of this work is to develop a numerical calculation program to study the effect of gas on the supersonic flow around a sharp airfoil in the context of a gas at high temperature (HT) below the threshold of dissociation of molecules by use of successive shocks and expansions on the airfoil surface. The airfoil is discretized into several consecutive segments on the extrados and intrados of the airfoil. The relations of an oblique shock wave (OSW) and the Prandtl Meyer expansion (PME) are used to determine the thermo-physical parameters on all segments including the Mach number, the pressure ratio, the temperature ratio, and the total pressure ratio in each segment considered to determine the aerodynamic coefficients of drag, lift, and pitching moment of the airfoil. The application is made for air and with 6 other gases which are H2, O2, N2, CO, CO2, and H2O. Three new comparison coefficients λD, λL and λM have been introduced to compare respectively the drag, lift and pitching moment coefficients of any gas compared to air for any sharp airfoils. So when a coefficient is less than unity, the gas considered has better performance compared to air for the corresponding gas dynamics coefficient. The application is made again for symmetrical curved airfoil given its practical interest in the international community. The validation is made by considering the calculation of the flow using the HT model at low temperature T0=500 K approximately, which represents the PG model threshold, the results of which for this last model can be found in the literature. The comparison of the results between the gases mentioned above and air shows the existence of a difference of 18.56%, 8.87%, 5.00% 2.39% 73.62% and 56.13% between the gases and air when M∞=5.00, T0=3500 K, α=2° and t/C=4% demonstrating the existence of gases more efficient than air in the field of aerospace construction. The application can be expanded for the design of future atmospheric and space vehicles.
Source: Brazilian Journal of Technology
DOI: 10.38152/bjtv7n4-006
Authors: Rahima Takhnouni, Toufik Yahiaoui
Institution: University of Blida
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4403996441