To develop a Source Panel Method Tool to Estimate Pressure Distribution over a 3D Non-Lifting Prolate Ellipsoid of Revolution

2021 ◽  
Author(s):  
Zulqarnain Ali ◽  
Hassan Khalid ◽  
Zeeshan Riaz ◽  
Talish Mahmood
Keyword(s):  
Pressure Distribution ◽  
Panel Method ◽  
Prolate Ellipsoid ◽  
Ellipsoid Of Revolution

scholarly journals Investigation of the Unsteady Flow Behaviour on a Wind Turbine Using a BEM and a RANSE Method

2016 ◽  
Vol 2016 ◽  
pp. 1-12
Author(s):  
Israa Alesbe ◽  
Moustafa Abdel-Maksoud ◽  
Sattar Aljabair
Keyword(s):  
Unsteady Flow ◽  
Wind Turbine ◽  
Pressure Distribution ◽  
Three Dimensional ◽  
Panel Method ◽  
Flow Behaviour ◽  
Viscous Effects ◽  
Horizontal Axis Wind Turbine ◽  
Local Flow ◽  
Ranse Solver

Analyses of the unsteady flow behaviour of a 5 MW horizontal-axis wind turbine (HAWT) rotor (Case I) and a rotor with tower (Case II) are carried out using a panel method and a RANSE method. The panel method calculations are obtained by applying the in-house boundary element method (BEM) panMARE code, which is based on the potential flow theory. The BEM is a three-dimensional first-order panel method which can be used for investigating various steady and unsteady flow problems. Viscous flow simulations are carried out by using the RANSE solver ANSYS CFX 14.5. The results of Case I allow for the calculation of the global integral values of the torque and the thrust and include detailed information on the local flow field, such as the pressure distribution on the blade sections and the streamlines. The calculated pressure distribution by the BEM is compared with the corresponding values obtained by the RANSE solver. The tower geometry is considered in the simulation in Case II, so the unsteady forces due to the interaction between the tower and the rotor blades can be calculated. The application of viscous and inviscid flow methods to predict the forces on the HAWT allows for the evaluation of the viscous effects on the calculated HAWT flows.

Panel method predictions of added mass for flexible airship

2013 ◽  
Vol 117 (1191) ◽  
pp. 519-531 ◽  
Author(s):  
M. Zhang ◽  
X. Wang ◽  
D. Duan
Keyword(s):  
Membrane Structure ◽  
Dynamic Models ◽  
Mass Matrix ◽  
Added Mass ◽  
Panel Method ◽  
Arbitrary Geometry ◽  
State Equations ◽  
Ellipsoid Of Revolution ◽  
And Control ◽  
Manipulation And Control

Abstract Because of the huge volume and inflated membrane structure of stratosphere airship, the deformation of stratosphere airship is very sensitive to the change of environment conditions such as wind, temperature and so on. The influence of deformation on manipulation and control is very remarkable. So, during the course of building flight dynamic model of the flexible airship, the added-mass matrix of deformation is very important part in the state equations of dynamic models. For obtaining the accurate added-mass matrix of different flexible airship, we proposed an approach that can calculate the added-mass matrix of a flexible airship with arbitrary geometry shape by the panel method. Through the comparison of results of computation and theory for ellipsoid of revolution and the flexible Skyship-500 airship, the proposed method can calculate the added-mass matrix for arbitrary geometric shape very accurately.

Aerodynamic Degradation of Iced Airfoils: Experiments and CFD Simulations

2009 ◽  
Author(s):  
Z. Chara ◽  
V. Horak ◽  
D. Rozehnal
Keyword(s):  
Wind Tunnel ◽  
Pressure Distribution ◽  
Cfd Simulation ◽  
Panel Method ◽  
Ice Accretion ◽  
Cfd Simulations ◽  
Ansys Cfx ◽  
Lift And Drag ◽  
Naca 0012 ◽  
Ice Shapes

The phenomenon of in-flight icing may affect all types of aircraft. Presence of ice on wings can lead to a number of aerodynamic degradation problems. Thus, it is important to understand the different ice shapes that can form on the wings and how they affect aerodynamics. When compared to wings without ice, wings with ice indicate decreased maximum lift, increased drag, changes in pressure distribution, stall occurring at much lower angles of attack, increased stall speed, and reduced controllability. The in-house ice accretion prediction code R-ICE using 2-D panel method was developed. The CFD simulation with the software ANSYS CFX 11.0 was used to simulate flow around iced airfoils NACA 0012. These airfoils were experimentally investigated in a wind tunnel. The paper presents a comparison of lift and drag coefficients experimentally observed and numerically simulated.

scholarly journals Comparison of Linear Vortex Panel Method and Finite Volume Method for Calculation of Generated Lift in Potential Flow Over Two-Dimensional Car Bodies

2020 ◽  
Author(s):  
Saeid Moammaei ◽  
Mehran Khaki Jamei ◽  
Morteza Abbasi
Keyword(s):  
Pressure Distribution ◽  
Lift Coefficient ◽  
Control Point ◽  
Panel Method ◽  
The Body ◽  
Aerodynamic Load ◽  
Two Dimensional ◽  
Algebraic Equations ◽  
Linear Algebraic Equations ◽  
The Impact

Abstract This paper describes one of the aspects of the panel method to analyze the aerodynamic characteristics of a sedan. The linear vortex panel method has been developed to simulate the ideal flow over a two-dimensional arbitrary car and, it also calculates the aerodynamic load on the body. By satisfying the boundary conditions on each control point, our linear algebraic equations are obtained. The results are sensitive to the distribution of the panels over the body thus the body is broken up equally into very small panels. After solving the set of equations, the vortices strength is obtained and the pressure distribution for the upper and the lower surface of the body is calculated. The impact of the angle of attack on the aerodynamic behavior of the intended car is investigated and it is found that the lift coefficient increases with the free stream angle from -4 to 4. The accuracy of the results has been determined by checking them against the standard CFD data. The pressure distribution trend is found very much in confirmation with the CFD results, however, a discrepancy at the rear end is observed. Therefore, it can be concluded that this method does not seem practical for geometries with steep slopes in the rear part of the car. Finally, both methods are applied to the other modified geometries with lower slopes at the rear section and the results compare well with the fluent.

Flow patterns in models of small airway units of the lung

1972 ◽  
Vol 52 (1) ◽  
pp. 161-177 ◽  
Author(s):  
M. R. Davidson ◽  
J. M. Fitz-Gerald
Keyword(s):  
Circular Cylinder ◽  
Boundary Conditions ◽  
Finite Length ◽  
Stokes Equations ◽  
Gas Transport ◽  
Flow Patterns ◽  
Small Airway ◽  
Creeping Flow ◽  
Prolate Ellipsoid ◽  
Ellipsoid Of Revolution

Quasi-steady creeping flow in models of small airway units of the lung is investigated. A respiratory unit of the lung is modelled by a sphere, an oblate and a prolate ellipsoid of revolution, and a circular cylinder of finite length. The solution of the Stokes equations for each of these geometries is indicated for general axi-symmetric boundary conditions. For particular cases consistent with the models, streamlines are plotted and some velocity profiles are shown. It is suggested that bulk 00w in the ha1 generations of the lung is significant for gas transport even though diffusion is the predominant mechanism there.

Analysis of the Flow Around Supercavitating Hydrofoils with Midchord and Face Cavity Detachment

1991 ◽  
Vol 35 (03) ◽  
pp. 198-209
Author(s):  
Spyros A. Kinnas ◽  
Neal E. Finer
Keyword(s):  
Pressure Distribution ◽  
Integral Equations ◽  
Inviscid Flow ◽  
Panel Method ◽  
Pressure Side ◽  
Flow Conditions ◽  
Trailing Edge ◽  
Pressure Distributions ◽  
Work First ◽  
Flow Criterion

In this work, first the linearized supercavitating hydrofoil problem with arbitrary cavity detachment points is formulated in terms of unknown source and vorticity distributions. The corresponding integral equations are inverted analytically and the results are expressed in terms of integrals of quantities which depend only on the hydrofoil shape. These integrals are computed numerically, in an accurate and efficient way, to produce cavity shapes and pressure distributions on the foil and cavity. The effect of the cavity detachment points on the shape of the cavity and the foil pressure distribution is investigated. An inviscid flow criterion for the cavity detachment point is derived for the case where the cavity detaches in front of the trailing edge on the pressure side of the hydrofoil. Finally, the accuracy of the linearized cavity theory is assessed for different foils and flow conditions, by analyzing the produced cavity shapes with a nonlinear panel method.

A Surface Panel Method for Design of Hydrofoils

1994 ◽  
Vol 38 (03) ◽  
pp. 175-181
Author(s):  
Chang-Sup Lee ◽  
Young-Gi Kim ◽  
Jung-Chun Suh
Keyword(s):  
Integral Equation ◽  
Boundary Value Problem ◽  
Pressure Distribution ◽  
Three Dimensional ◽  
Panel Method ◽  
Simultaneous Equations ◽  
Surface Panel Method ◽  
Total Potential ◽  
Pressure Distributions

A surface panel method treating a boundary-value problem of the Dirichlet type is presented to design a hydrofoil corresponding to a prescribed pressure distribution. An integral equation is derived from Green's theorem, giving a relation between the total potential of known strength and the unknown local flux. Upon discretization, a system of linear simultaneous equations is formed and solved for an assumed geometry. The pseudo local flux, present due to the incorrect positioning of the assumed geometry, plays a role of the geometry corrector, with which the new geometry is computed for the next iteration. Sample designs for a series of pressure distributions of interest are performed to demonstrate the fast convergence, effectiveness and robustness of the procedure. The method is shown equally applicable to designing two- and three-dimensional hydrofoil geometry.

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