Hydrofoil Flow
THIS INTERACTIVE JAVA APPLET WAS DEVELOPED AT UT AUSTIN
BY Chris Jenkins AND Lino Geo Lino Bailey, UNDER THE SUPERVISION OF PROFESSOR.
Spyros A. Kinnas, 2000.
PERMISSION TO LINK TO THIS JAVA APPLET AND TO DOWNLOAD
OR TO USE THE RELATED JAVA SOURCE CODE, MUST BE GRANTED BY PROFESSOR Spyros
A. Kinnas ( kinnas@mail.utexas.edu
).
Purpose:
This applet uses a numerical method (a panel method based on the total velocity potential)
to calculate and plot the pressures on the surface of a hydrofoil
subject to a uniform inflow.
Assumptions:
-
The flow is assumed to be inviscid and incompressible (rho is the density of the fluid).
-
The hydrofoil is a NACA 4-digit thickness form combined
with parabolic camber.
-
The inflow velocity vector is U, the chord of the foil c, and the ambient pressure po.
- The values of U, c, rho, and po are not needed as the pressures along the
foil surface are given in terms of the negative pressure coefficient,
defined as -Cp=-(p-po)/(0.5*rho*U^2)
-
Arc lengths are approximated in the calculation
using the linear distance between panel
discretization points.
Using the applet:
-
Click on 'Open Window' to start the applet.
-
Input the angle of attack in degrees and press enter.
-
Input the max. camber/chord, f/c, in the range [-0.25, 0.25] and press enter to determine
the mean camberline distribution.
-
Input the max. thickness/chord, t/c, in the range [0.025, 0.5] and press enter to determine
the thickness distribution.
-
Choose the number of panels, N, in the range [60, 200].
N must be even in order
to use the same number of panels at the top and the bottom of the foil.
-
Click on 'Go' to begin calculating the influence coefficients
and solve for the potential distribution on the foil surface. The location
of the panel mid-points (also called the control points) is shown on the
screen (starting from the bottom trailing edge), together with the normal vector
on all other panels and the corresponding subtended angles (both used in the
calculation of the influence coefficients).
- Once the calculation is completed, the computed -Cp along the top side (called the suction side or the "back") and the
bottom side (called the pressure side or the "face") of the foil will show in a separate pop-up window.
You can enlarge, close or leave open the pop-up window with the results. You can change the foil characteristics
or number of panels and perform as many more runs as you wish (...or as many open windows you
can take)
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Last
Revised: May 25, 2000