Role of solution reconstruction in hypersonic viscous computations using a sharp interface immersed boundary method

Area of Science:

• Computational Fluid Dynamics
• Hypersonic Flow Physics
• Numerical Methods

Background:

• Accurate computation of wall shear and heat fluxes is critical for hypersonic flow analysis.
• Immersed boundary (IB) methods offer flexibility in handling complex geometries but require careful validation for accuracy.

Purpose of the Study:

• To develop and assess a sharp interface immersed boundary (IB) finite-volume (FV) method for viscous compressible hypersonic flows.
• To investigate the accuracy of the IB-FV solver for computing wall shear and heat fluxes.
• To identify and analyze the sources of error in heat flux predictions.

Main Methods:

• Implementation of a sharp interface IB method within an unstructured Cartesian finite-volume framework.
• Direct imposition of boundary conditions using a local reconstruction approach on nonconformal meshes.
• Numerical investigation of canonical high-speed viscous flows across various Mach numbers.

Main Results:

• The IB-FV solver accurately computes surface pressure and shear stress distributions.
• Surface heat fluxes are underpredicted for aerodynamically blunt configurations.
• Error analysis reveals that solution reconstruction, particularly temperature reconstruction, is a more significant source of heat flux underprediction than grid resolution.

Conclusions:

• Existing polynomial-based reconstruction approaches in sharp interface IB methods are inadequate for accurate heat transfer predictions in high Reynolds number hypersonic flows.
• Linear interpolations for temperature reconstruction can lead to significant errors in heat flux estimation.
• Further development of reconstruction techniques is necessary for reliable heat transfer simulations in hypersonic regimes.