Subsonic Performance Research Articles

Numerical investigation for subsonic performance of the high-pressure capturing wing configuration with wing dihedral

High-pressure capturing wing (HCW) aerodynamic configuration demonstrates favorable aerodynamic performance under hypersonic conditions, and its novel additional lifting wing (also known as HCW) has the potential to enhance lift characteristics under subsonic conditions. Therefore, this configuration presents a promising option for wide-speed-range vehicles. However, the stability characteristics of this novel configuration under subsonic conditions have not yet been investigated. In this paper, the effects of wing dihedral angles on the subsonic aerodynamic characteristics of a parametric conceptual HCW configuration with two lifting wings were investigated. Specifically, the design variables for this study were the dihedral angles of the upper HCW and the lower delta wing. To obtain the distributions of various aerodynamic parameters over the design space, a combination of the uniform experimental design method, computational fluid dynamics numerical simulation techniques, and kriging surrogate model algorithm was employed. The findings suggest that wing dihedral angles have a greater impact on the lift-drag ratio (L/D) at low angles of attack compared to high angles of attack. L/D can be enhanced by incorporating a positive dihedral angle in HCW, and as the delta wing's negative dihedral angle rises, L/D tends to increase earlier and decrease later at low angles of attack. Furthermore, for the longitudinal, lateral, and directional stability characteristics of this configuration, the positive dihedral angles of the delta wing offer greater overall advantages than negative ones in improving them, and the positive dihedral angles of HCW yield more significant enhancements in stability compared to negative ones.

The inlet flow structure of a conceptual open-nose supersonic drone

This study describes the aerodynamic efficiency of a forebody–inlet configuration and computational investigation of a drone system, capable of sustainable supersonic cruising at Mach 1.60. Because the whole drone configuration is formed around the induction system and the design is highly interrelated to the flow structure of forebody and inlet efficiency, analysis of this section and understanding its flow pattern is necessary before any progress in design phases. The compression surface is designed analytically using oblique shock patterns, which results in a low drag forebody. To study the concept, two inlet–forebody geometries are considered for Computational Fluid Dynamic simulation using ANSYS Fluent code. The supersonic and subsonic performance, effects of angle of attack, sideslip, and duct geometries on the propulsive efficiency of the concept are studied by solving the three-dimensional Navier–Stokes equations in structured cell domains. Comparing the results with the available data from other sources indicates that the aerodynamic efficiency of the concept is acceptable at supersonic and transonic regimes.

Planform-customized waverider design integrating with vortex effect

The global geometric relationship among the inlet capture curve, flow capture tube and planform contour line in the osculating-cone waverider design is deduced by a differential equation set. Planform-customized waverider is enabled to be constructed based on the geometric relationship. Thus the configuration with satisfactory wide-velocity-range performance is proposed, employing vortex effect to improve subsonic performance and shock effect to improve super/hypersonic performance, respectively. To validate the concept, the double swept waveriders are generated as test cases. Compared with flat plate models, the aerodynamic performance and flow mechanics of the double swept waverider are analyzed under subsonic and hypersonic conditions using computational fluid dynamics (CFD) simulation. CFD results show that the performance of the waverider with reasonable planform is favorable under both subsonic and hypersonic conditions, remedying some deficiencies of traditional waverider. The work demonstrates a new thought for wide-velocity-range configuration design.

History of the Pegasus vectored thrust engine

History of the Pegasus vectored thrust engine

Errata-Integrated Scramjet Installation Effect on the Subsonic Performance of a Hypersonic Aircraft

Errata-Integrated Scramjet Installation Effect on the Subsonic Performance of a Hypersonic Aircraft

Integrated Scramjet Installation Effect on the Subsonic Performance of a Hypersonic Aircraft

Integrated Scramjet Installation Effect on the Subsonic Performance of a Hypersonic Aircraft

Opening distance of a parachute

Opening distance and inflation time prediction for parachutes deployed supersonically based on subsonic performance