Flow Characteristics of a Mixed Compression Hypersonic Intake

Abstract

The flow field in a two-dimensional hypersonic mixed-compression inlet in a freestream Mach numbers of M∞ =2.0, 3.0, and 5.0 are numerically solved to understand the effect of throat area variation. The exit area ratio variation is simulated by placing a plug insert at different axial locations at the exit of the model. The flow field is achieved computationally by solving the Reynolds Averaged Navier-Stokes equations in a finite volume framework. For each flow condition, the variation in shock structure is analyzed and the variation of the oblique shock wave angle with the mass flow rate is calculated theoretically and compared with the present CFD analysis. The variation in oblique shock angle is calculated in terms of the mass flow rate by considering the capture area and spillage flow through the inlet. The theoretical results suggest that the method can predict the inlet operating conditions at different freestream Mach numbers and area ratios. This method can quantify the reduction in mass flow rate due to the throttling effect by analyzing the flow field shock pattern. The effects of various important performance parameters such as free stream Mach number, total pressure recovery, and mass flow ratio were then numerically investigated. As the Mach number is increased, the total pressure recovery is reduced, but the maximum value of the mass flow rate is increased. The analysis is also focused on the effect of throat area variation on performance parameters at each Mach number. The characteristic curve of the inlet is then obtained for each free stream Mach number.

Self-Start Characteristics of Hypersonic Inlet When Multiple Unstart Modes Exist

“…Equation ( 1) is the conservation form of compressible Navier-Stokes equations. The calculation object was perfect gas (air) [9,13,15,48], and the fluid's viscosity was computed using the Sutherland equation. Since the calculation problem concerned compressible flow, and in order to address to the calculation accuracy and efficiency, a density-based solver conducted via an implicit time integration method and second-order upwind ROE difference scheme was chosen to solve the complex problem.…”

“…In a hypersonic inlet, large-scale separated flow is easily induced when intense lip shock compacts into the opposite boundary layer. The status of the inlet then becomes unstart, which is the most conventional unstart mode [13][14][15][16]. The oscillation of the unstart mode is stronger than that of the start mode, which is affected by factors including the boundary layer [17] and back pressure [18].…”

Passive flow modification over the supersonic and the hypersonic air-intake system using bleed

“…The inlet should provide better performance for its alloperating condition. Because of the high operating range of Mach numbers, the mixed compression type of inlet is the most convenient [5]. Flow field for the mixed compression type of inlet as shown in Figure 1.…”

Numerical Study of Aerodynamic Characteristics of a Pointed Plate of Variable Elongation in Subsonic and Supersonic Gas Flow

“…In particular, in computational aerodynamics, pointed wedges are used to generate shock waves [6]. The same problems are also of interest for calculation of hypersonic air intakes and subsonic diffusers [7,8]. It should be noted that modern aircraft and structural elements can change its aerodynamic configuration in flight due construction features, or physical phenomena, that results in changes in aerodynamic characteristics [9][10][11].…”