A hybrid Navier-Stokes/full-potential method for the prediction of iced wing aerodynamics

1994 ◽  
Author(s):  
O. Mello ◽  
L. Sankar
Keyword(s):  
Potential Method ◽  
Navier Stokes ◽  
Full Potential ◽  
Wing Aerodynamics

Parameter Extension Simulation of Turbulent Flows in a Compressor Cascade With a High Reynolds Number

2020 ◽  
Author(s):  
Yan Jin
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Stokes Equations ◽  
Simulation Method ◽  
Potential Method ◽  
Navier Stokes ◽  
Reference Solution ◽  
Compressor Cascade ◽  
High Reynolds

Abstract The turbulent flow in a compressor cascade is calculated by using a new simulation method, i.e., parameter extension simulation (PES). It is defined as the calculation of a turbulent flow with the help of a reference solution. A special large-eddy simulation (LES) method is developed to calculate the reference solution for PES. Then, the reference solution is extended to approximate the exact solution for the Navier-Stokes equations. The Richardson extrapolation is used to estimate the model error. The compressor cascade is made of NACA0065-009 airfoils. The Reynolds number 3.82 × 105 and the attack angles −2° to 7° are accounted for in the study. The effects of the end-walls, attack angle, and tripping bands on the flow are analyzed. The PES results are compared with the experimental data as well as the LES results using the Smagorinsky, k-equation and WALE subgrid models. The numerical results show that the PES requires a lower mesh resolution than the other LES methods. The details of the flow field including the laminar-turbulence transition can be directly captured from the PES results without introducing any additional model. These characteristics make the PES a potential method for simulating flows in turbomachinery with high Reynolds numbers.

A Navier-Stokes/full potential/free wake method for rotor flows

1997 ◽  
Author(s):  
Mert Berkman ◽  
Lakshmi Sankar ◽  
Charles Berezin ◽  
Michael Torok ◽  
Mert Berkman ◽  
...  
Keyword(s):  
Navier Stokes ◽  
Full Potential ◽  
Free Wake

Navier-Stokes/Full Potential/Free-Wake Method for Rotor Flows

1997 ◽  
Vol 34 (5) ◽  
pp. 635-640 ◽  
Author(s):  
Mert E. Berkman ◽  
Lakshmi N. Sankar ◽  
Charles R. Berezin ◽  
Michael S. Torok
Keyword(s):  
Navier Stokes ◽  
Full Potential ◽  
Free Wake

THE WING-BODY AEROELASTIC ANALYSES USING THE INVERSE DESIGN METHOD

2010 ◽  
Vol 24 (13) ◽  
pp. 1479-1482
Author(s):  
SEUNG JUN LEE ◽  
DONG-KYUN IM ◽  
IN LEE ◽  
JANG-HYUK KWON
Keyword(s):  
Design Method ◽  
The Body ◽  
Inverse Design ◽  
Navier Stokes ◽  
Full Potential ◽  
Small Disturbance ◽  
Body Effect ◽  
Flow Equations ◽  
Applicable Range ◽  
Inverse Design Method

Flutter phenomenon is one of the most dangerous problems in aeroelasticity. When it occurs, the aircraft structure can fail in a few second. In recent aeroelastic research, computational fluid dynamics (CFD) techniques become important means to predict the aeroelastic unstable responses accurately. Among various flow equations like Navier-Stokes, Euler, full potential and so forth, the transonic small disturbance (TSD) theory is widely recognized as one of the most efficient theories. However, the small disturbance assumption limits the applicable range of the TSD theory to the thin wings. For a missile which usually has small aspect ratio wings, the influence of body aerodynamics on the wing surface may be significant. Thus, the flutter stability including the body effect should be verified. In this research an inverse design method is used to complement the aerodynamic deficiency derived from the fuselage. MGM (modified Garabedian-McFadden) inverse design method is used to optimize the aerodynamic field of a full aircraft model. Furthermore, the present TSD aeroelastic analyses do not require the grid regeneration process. The MGM inverse design method converges faster than other conventional aerodynamic theories. Consequently, the inverse designed aeroelastic analyses show that the flutter stability has been lowered by the body effect.

First-Principles and Experimental Study on Cu Doped SnO2 Structure

2013 ◽  
Vol 470 ◽  
pp. 35-38 ◽  
Author(s):  
Lin Ting Shan ◽  
De Chun Ba ◽  
Xiao Bo Han
Keyword(s):  
Thin Films ◽  
First Principles ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Rutile Phase ◽  
Potential Method ◽  
Full Potential ◽  
X Ray Diffraction ◽  
Copper Addition ◽  
Linearized Augmented Plane Wave

SnO2 and Cu-SnO2 thin films were fabricated by the sol-gel method. The influence of annealing temperature and copper addition on the morphology and microstructure of the films was studied using X-ray diffraction (XRD) and UV-Visible, respectively. The results show that the tetragonal rutile phase is evidenced by XRD with no other phases observed. The crystallinity of SnO2 and Cu-SnO2 thin films had been improved with the increasing annealing temperature. The grain size decreased after Cu doping. On theoretical, Pure and Cu-SnO2 were calculated by first-principles full potential linearized augmented plane wave ultra-soft pseudo-potential method to investigate band structure.

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