Aerodynamic and heat transfer correlations for smooth and rough airfoils

Abstract

The problem of icing in aircrafts is known as one of the most critical issues for the aviation community as this matter is directly connected to the flight safety. Due to the high cost of flight tests, many experiments and numerical models have been used to model the icing condition and the influence of the flight. In particular, an accurate estimation of the heat transfer is needed for preliminary design of the anti-icing and de-icing systems. Therefore, the goal of this thesis is to propose a correlation for smooth airfoils before icing (anti-icing systems) and rough airfoils after the ice accretion (de-icing systems) to predict the heat transfer Nusselt number and aerodynamics coefficient. The CFD is used as a high-fidelity method to predict the heat transfer on the smooth and rough airfoils, before and after icing conditions. To have a better understanding of CFD and aircraft icing, the literature review of this thesis is dedicated to a discussion about the history of icing studies and the necessity of continuous icing research, in spite of the numerous achievements. Also, the numerical modelling for icing is discussed in this section. The Spalart-Allmaras turbulence model (SA-SMOOTH) for the smooth airfoils and the Spalart-Allmaras turbulence model with the roughness modification (SA-ROUGH) for the rough airfoils are chosen to build the database. Before building the aerodynamics and heat transfer database, the CFD results are validated and verified against prior experimental and numerical results. Also, to ensure the reliability of the results, the quality of the meshes are evaluated with the GCI method. The database is built for the NACA 0009, NACA0012, and NACA0015 airfoils with □ = 0.625 × 10଺, 1.25 × 10଺, 2.5 × 10଺, □ 5 × 10଺ and 0 ͦ ≤ □ ≤ 13 ͦ for the smooth and 0 ͦ ≤ □ ≤ 9 ͦ for the rough airfoils. The Nusselt number and the drag coefficient are then plotted as a function of the lift coefficient to derive the correlation. Three drag coefficient correlations for the □ and □௠௜௡ for the smooth and □௠௜௡□ for the rough airfoils are proposed with three Nusselt number correlations including □௔□௚ for the general correlations and □௠௔□ and □௠௔□□ for the smooth and rough airfoils initial values. To verify the proposed heat transfer correlation, the new proposed correlation is compared with a previous work for the smooth surface.

Date	11 Jul 2022
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	François Morency (Supervisor)