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CFD Visualization

Selected CFD plots will be presented here as available. These visualizations were produced by Boyko Tchavdarov using CFD2000 Software

Click on any image to bring up a larger version in a second window.

The following plots present information on the low-speed (60 mph) aerodynamic characteristics of a candidate duct design at 12 degrees and 24 degrees angle of attack (post-stall). Simulations were performed using Navier-Stokes methods which permit predictions of turbulent flow.

Duct Geometry (small)

Hummingbird's Duct Geometry

This won't tell you much about aerodynamics, but it may whet your appetite if you enjoy the beauty of curvacious flying surfaces.
Duct Pressures Mid (small)

Pressure Contours at Duct Mid-Plane

These plots offer some insight into the influence of duct camber (inlet diameter/outlet diameter) on the complex pressure fields around and within the duct when producing lift.
Duct Pressures (small)

Pressure Contours on Duct Surface

This plot should settle one question once and for all: Yes, a duct can do double-duty as a lifting surface.
Duct Streamlines (small)

Streamlines around Duct Surface

These streamline patterns provide a subjective impression of how much air the duct can move around, even at 24 degrees angle of attack (post stall) and 60 mph! At this airspeed the duct chord Reynolds number is only about 1.5 million.
Duct Stall (small)

Duct Stall Pattern

This very revealing plot demonstrates one reason why annular wings have so much potential for aerobatics. At 24 degrees angle of attack the duct is still lifting powerfully and the inside surface stall pattern has reached forward only about as far as the aft propeller - this almost 5 degrees after the wings have stalled! Notice the vortices coming off the sides of the duct - analogous to a "tip vortex".
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© Copyright 1992-2009 Philip Carter