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COBEM 2021
26th International Congress of Mechanical Engineering
AERODYNAMIC HEATING OF AN HYPERSONIC AIRBREATHING VEHICLE AT MACH NUMBER 5.8
Submission Author:
Paulo Ce´sar de Oliveira Júnior , RN , Brazil
Co-Authors:
Paulo Ce´sar de Oliveira Júnior, George Marinho, Paulo Toro, João Carlos Arantes Costa Júnior
Presenter: Paulo Ce´sar de Oliveira Júnior
doi://10.26678/ABCM.COBEM2021.COB2021-0818
Abstract
In the aerospace sector there is a major limitation related to the payload that can be launched into orbit or beyond, due to the weight of the propulsion systems with chemical combustion, which are on board, currently used. In this context, several important studies carried out in the area of hypersonic propulsion, focusing on scramjet engines, which allow a greater payload because they do not need the oxidizer on board. Aerospace vehicles that use the hypersonic airbreathing propulsion system must include the conditions of hypersonic flight, resulting from aerodynamic and thermal loads. The hypersonic flight introduces extreme thermal loads at the vehicle's leading edges, resulting in high temperature around the surface; this effect is due to the transformation of the kinetic energy of the flow into thermal energy, producing a phenomenon called aerodynamic heating. Understanding this phenomenon is of paramount importance for determining the material to be used in the coating of the hypersonic aerospace vehicle, ensuring thermal protection to maintain the temperature of its internal walls at acceptable levels, as well as avoiding telemetry problems. Thus, the present work has as main objective to estimate the levels of heat flux (aerodynamic heating) to which the scramjet technological demonstrator will be subjected during an atmospheric flight at an altitude of 23 km and with a speed of 1723 m/s, corresponding to the number of Mach 5.8. Fay and Riddell, Lees, and Eckert methods are applied at the stagnation point, stagnation region, and at flat plate segments, respectively, for determining aerodynamic heating the at the aerospace vehicle integrated with a scramjet. The heat flux at the stagnation point is 2,558,209.22 W/m² and corresponds to the highest value found for the scramjet. At the intersection of the cylinder section and the deflection of the first ramp, a heat flux of 166,435.60 W/m² was verified, demonstrating the efficiency of the blunted region in reducing aerodynamic heating. In the ramps there is an increase in heat flux, but these values are significantly lower than the stagnation point and decrease along the flat region.
Keywords
aerospace vehicle, Scramjet, Heat flux, hypersonics
