Recent content by DickL

Many years back, I read the navy was experimenting with or using rocket assisted projectiles to increase the range of ship board guns. Claims were that a 5 in. gun, using a rocket assisted projectile, would have the same range as a 16 inch gun with conventional projectiles. I don't know if this...

jimhebert, you raise a good point. You are probably right that air and water are mixed prior to entering the turbine. The mixing and creation of small bubbles probably occurs mostly right in the entry of to the turbine (that's my guess). Water could be brought into the shaft by a hole, or series...

It is a centrifugal pump and works the same as all centrifugal pumps. How long the blades are (along the radius) will effect the head (pressure or suction) developed. The curvature of the blades (or lack) will have some effect on the performance versus speed and the noise output. When the pump...

Yes, that is my suggestion, unless the need is for a high precision result. I suspect that the thread engagement efficiency may be more important than the error resulting from my simplification. Do not expect to get equal loading all along the threads, and as the loading builds up there will...

You might also look at the rfi tags used in some prostrate radiation work (and I suspect other applications).

Why don't you try unwinding the helix such that it becomes an inclined plane and use simple geometry. Find the area for 1 full revolution and then determine the number of threads engaged.

In simple bending, the solid shaft will be stronger, but ... There is more to consider. For large diameter shafts the weight of the shaft becomes a significant bending load that must be added to the applied load. For a large diameter shaft, a hollow shaft may support a greater applied load. Why...

If there is a some friction between balls, when a trailing ball rolls into a leading ball, the mutual rotation of both balls, plus the ball against ball friction causes the trailing ball to rapidly climb, almost straight up. I'm familiar with this phenomenon from open wheel racing when I was...

There are several reasons why trains weight a lot more than just the passenger weight. Locomotives need to weigh quite a bit in order to pull a train, roughly 10% of the maximum weight train they will pull. Rail cars are also built heavy to provide the structural strength and stiffness to stand...

Ron Hock has written a book, 'The Perfect Edge', which mostly explains how to sharpen woodworking tools (chisels, plane blades, etc.). It also provides a good explanation of what is happening and how the type and metallurgic treatment of the steel effects the sharpening, including some micro...

I suspect, based on some experience riding water lubricated slides, that a hydrodynamic bearing is being formed under the slider. My guess is that larger people present a greater area to the water/slide interface and thereby create a more effective hydrodynamic bearing, and therefore a lower...

You could use a cam to raise the hammer and let it fall. The cam would have a gentle slope for raising the hammer, with a step change to let the hammer free fall. Such mechanisms were used with water power from the middle ages on, and are still used in some industrial processes. The rate of...

Consider using the mechanism that Mercedes uses for their single wiper blade systems. It is similar to your original suggestion of a gear running against a rack. Rather than a gear with teeth only on apart of the gear, it is a normal spur gear. The rack has its teeth running completely around a...

But what does this have to do with a skier falling down. I rarely do a time, speed distance computation when I fall while skiing. However, based on some personal experience, the hill's slope has a significant impact on the dynamics of the fall. Also the forward velocity (or more correctly the...

I'm going with - it depends. Back in WWI, the German Paris gun was aimed at something around 50 or 55 degrees to be the maximum range. The explanation was that at high altitudes (45,000 ft and above) the air was thinner and offer less resistance and most of the projectile's flight was above 45k...