Recent content by Hawknc

There are a number of drag coefficients, each of them relating to the specific drag that you're calculating at the time. Scramjet posted the correct equation for calculating skin friction. The Reynolds number is important because it gives you an idea of the ratio of viscous forces to inertial...

The Chaser's War on Everything is all pure gold, baby. Google video Australia has plenty more of their clips.

Except it's not really anything at all like the Wii, is it? It's essentially what Microsoft was doing five years ago with PC controllers, and they've only just now caught up. The Wii takes the same fundamental idea and makes it useable in just about any situation, rather than simply...

Not to mention google.org's alternative energy car that they're developing...it'll be interesting to see how effectively a for-profit charity operates.

The force of static friction is measured in Newtons, it's what acts on the car to keep it from sliding. The coefficient of static friction is a dimensionless number, usually less than 1. I can tell you right now that a car's friction force will be quite a bit greater than 0.27N...

This is a poor quality rip-off at best. It's Lucas' attempt to get the fans off his back about releasing the versions he wishes he never made. By releasing this laserdisc copy onto DVD, he can say he's given us what we want and point out that nobody bought it, when what we wanted in the first...

Honestly, what you typed seems reasonably specific. You could throw drag into the mix if you wanted as well - that's quite an important factor when considering flap angles, otherwise everyone would just fly full flaps. ;) You could measure the lift and drag forces on the aerofoil and determine...

That's essentially what happens in Australia (well, 49% or so). There are ways around it, of course, but basic income tax is at 49 cents in the dollar for the top bracket. That doesn't include fringe benefits tax, capital gains, GST...admittedly, for this we get a two-tier educational system in...

The first equation in that image is just Equation 4 rewritten for D and is probably still the more useful one. Do you know the difference between yield strength and ultimate tensile strength?

The shear modulus relates stress and strain, it's a measure of the stiffness of the material. It's really only relevant in this case if you want to know the deflection of the shaft. The maximum shear stress is probably the more relevant property for what you want, and it's a material property...

You've got two equations there and just the one variable to solve for (radius/diameter, whichever one takes your fancy). If anything, you have too much information. You can rearrange and substitute to get the variable you want if you know all the other values. All you should really need is...

The fluids lab at my uni do a lot of simulations regarding blood flow around anyeurisms, stents and the like. My project supervisor certainly seems to think there's plenty of crossover between the fields.

To just add a quick bit, turboprops are at their most efficient at around Ma = 0.5 or so, from memory, which makes them great for efficient travel at fairly low speeds. As Russ said, they can also provide a lot of power at takeoff, shortening the runway length required (the Caribou is a...

What will replace oil? If that ain't the $64 billion question, I don't know what is.:biggrin:

For Newtonian fluids I think it's fine; to be honest, I've never come across a situation where I've had to do that, but I can't think of a reason off the top of my head that it wouldn't be at least reasonably accurate.