This page is the portfolio of Hyunbin Kang, a master's student at Inha University, Department of Aerospace Engineering, Aerodynamic Analysis and Design Lab.

Name : Hyunbin Kang

Major : Computational Fluid Dynamics

• High Order Methods
• Hypersonic Aerodynamics
• Panel Methods

Education

• Inha University, Department of Aerospace Engineering, Bachelor's Degree (2017-2022)
• Inha University, Department of Aerospace Engineering, Master Course (2023-)

Email : [email protected](personal), [email protected](education)

Office : Inha University (Aerospace Campus), 36 Gaetbeol-ro, Yeonsu-gu Incheon 21999, Korea

About the projects I was involved in during my Master's Course.

Korean Society for Aeronautical and Space Science

Comparison of Flow Simulation over Low Reynolds Number Airfoil by Accuracy of PyFR

Intro :

• In this study, aerodynamic investigation was conducted with Low Reynolds Number Airfoil of EFD-CFD workshop 5th case *.
• LRN airfoil has complex flow structure, so accurate computational is needed.
• In this study, We utilze the PyFR, a aerodynamic analysis framework using Large Eddy Simulation (LES)

Results :

Spanwise effect

• Shorter spanwise length case has pool results of lift coefficients.

  
  lift curve with several spanwise length

• This result is caused by the 3-D effect of turbulent flow.

  
  Q-criterion at angle of attack of 10 degree

Laminar Separation Bubble (LSB)

• Low Reynolds number flow has a complex flow structure such as laminar separation, transition, reattachment etc.
• This LSB reduce the aerodynamic performance.
• LES can solve the LSB with high resolution.

International Conference of Spactral and High Order Method

Simulating Unsteady Flow over Low-Reynolds-Number Airfoil with Separation Bubble by PyFR

Intro :

• Based on the previous study (KSAS), parametric study is conducted for numerical and computational condition.
• Paramters : spanwise length, order of accuracy, grid system, and precision

Results :

Non-linearity

• LSB's movement cause the non-linear aerodynamic characteristics

  
  non-linearity of lift coefficient

  
  

  time-averaged x directional velocity contour

  
  time-averaged pressure coefficient distribution

Stall structure :

• At high angle of attack region, LSB is genarated at leading edge of airfoil.
• Since the strong separation can't recover the pressure, full separation from LE to TE is captured.

  
  time-averaged x directional velocity contour at high angle of attack

Discussion :

effect of Spanwise length

• We compared the result with (0.05, 0.1, 0.25, 0.5, 1.0) times of the chord length
• Short span is limited in including 3-D effect
• In high AoA region, spanwise length of 0.5 times of chord length is needed at least.

effect of Order of accuracy

• We performed the simulation with P2, P3, and P4 order with coarse, medium, and fine grid respectively
• If the grid is fine near the surface and wake region, there are slight difference in the case of P2 order compared with P2 and P3 order.
• The simulation with P2 coarse grid has inaccurate result. So lower order case has strong grid dependency.

effect of Grid system

• We constructed structured grid by PointWise and unstructured grid by Gmsh.
• There are no sigmificant difference with two grid system.
• However, there notable difference in computation time
• Unstructured grid's minimum edge length and minimum cell volume is 4 and 13 times smaller than structured grid. So the computation time of unstr case is 9 times larger than the structured case.

effect of precision

• There are no siginficant difference with single and double precision(FP32 and FP64)

Research on developing a variable wake model for panel program

Intro :

• Panel method is one of fast techniques of the aerodynamic analysis
• Panel method use the virtal wake panel to predict the lift
• When solving for high angle of attack condition, fixed wake model issues
• So variable wake model must be developed