View Full Version : virtual experiment about hovercraft.

heidkin191 - n/a
30-Nov-06, 02:53 AM
hello everyone.

i've been assign by my lecturer to make a virtual experiment about fluid dynamics. so, i choose to hovercraft since it's deal with the wind.

i'm a newbie about hovercraft so, i done a little search on hovercraf. i've read the article from the download page about 'calculation of thrust in a sucted fan assembly for hovercraft'. there're somethings that i don't understand when i read it. http://hovercraft.org.uk/images/icons/smiley_icons/icon_sad.gif

i don't understand how to use the chart about fan performance in figure 1. how can i get the values stated in the chart? which equation should i use to get the velocity, thrust, power consumed at speed/pitch and modified thrust?

i kindly hope for everyone guidance.


thank you.

tonybroad - n/a
30-Nov-06, 07:44 AM
Why don't you ask your lazy lecturer to do a 'real' fluid dynamics experiment, i can suggest lots of experiments which will actually mean something and be useful to you.

sorry just me having a bad day

Tony (Lecturer)

Sean Atterbury - n/a
30-Nov-06, 11:04 AM
Cheer up Tony.. http://hovercraft.org.uk/images/icons/smiley_icons/icon_smile.gif

Sure you'l win next year.. http://hovercraft.org.uk/images/icons/smiley_icons/icon_biggrin.gif http://hovercraft.org.uk/images/icons/smiley_icons/icon_biggrin.gif

Paul Fitz - n/a
2-Dec-06, 10:00 PM
The article was intended to give a basic understanding of the maths involved in fan calculations from known fan/engine data. It does not go back to first principles.

The chart (fig 1) is calculated from manufacturers data for a specific fan that was derived from test data. e.g If you use equation 4, (static thrust) for that size fan at 2500rpm and 35 degree pitch, you will arrive at a thrust figure of 1454N (181 lbf). this varies slightly from the chart(179), due to rounding errors in the calculation and variance in the original data. The figure for modified thrust is a crude approximation obtained by removing 4cu.m/sec of volume from the original fan Vd.

If you require the formulae to calculate the figures from first principles, you would be better researching thrust from propellers, as the information is more readily available on the internet.

This might be a good starting point.



Propeller/fan calculations are usually crude anyway, as assumptions have to be made about the efficacy of the thrusters. As Tony (despite his bad hair day) has suggested there are better avenues for exploring fluid dynamics.

heidkin191 - n/a
17-Dec-06, 03:05 AM
may i know how to increase the acceleration of the hovercraft when it's started to move? the theory, formulae, anything.