Heat and drag reduction on the hypersonic nose with a nexus between active and passive control methods

This study aimed to conduct an active, passive, and hybrid control analysis on the hypersonic drag and thermal reduction. To achieve this, the Reynolds-averaged Navier–Stokes equations were utilized, along with the shear-stress transport turbulence model. To this purpose, the total pressure ratio, the diameter of the opposing jet outlet, and the number of aerodisks are considered as variable parameters. By combining the above parameters, six different configurations were created. Configuration 1 includes a spike, one aerodisk, and an opposing root jet. In configurations 2–5, the number of aerodisks increments and there is no opposing root jet. Configuration 6 includes a spike, four aerodisks, and an opposing root jet. After validation and analysis of the grid independency, the effects of opposing root jet pressure in values of 0.1, 0.3, 0.5, and 0.7, the diameter of opposing root jet outlet (2, 4, and 6 mm), and the number of aerodisks (1, 2, 3, and 4) were examined thoroughly. In comparison with the optimal parametric model in configuration 1, which has a 6 mm outlet diameter and a total pressure ratio of 0.7, the parametric model under consideration exhibits reductions of 9.96% in the overall drag coefficient, 15.03% in the peak pressure, and 20.8% in the peak heat flux. However, configuration 6 has a noticeable and significant advantage in terms of stability of flow fluctuations in front of the nose. Therefore, due to the superiority of configuration 6 in terms of the stability of the flow fluctuations in front of the nose, which is an important factor in the stability of the aircraft, this configuration is the best among the configurations analyzed in this article.