Recent content by bill nye scienceguy!

Hiya I need to spec up a ventilation system for a small welding and machine shop. The area will have ten welders, one large vertical machining centre, a bunch of small machine tools and things like air compressors, heat treatment, small(ish) cranes and air compressors etc. My question is...

Your first mistake was to use Solidworks. In my experience (admittedly a few years ago now) Solidworks is workable if you want to compare flow paths on, for example, different iterations of a model but if you're after an absolute value don't bother.

I just asked google about inductive loads and I got this. http://www.markallen.com/teaching/ucsd/147a/lectures/lecture3/3.php It explains that inductive loads involve magnetic fields eg in a motor. It goes on to say that resistive loads convert electrical energy into another form of...

Ok, so is it safe to assume a power factor of 0.8 in estimating kVA? I say 0.8 since this seems to be quite common.

Ok, this is starting to make sense. To check my understanding: if something has a power rating of 600kVA and 480kW that means there's a power factor of 0.8? And in words that means that means that there is 600kVA total power in the system and 480kW is dissipated by the load. Assuming I have...

Sorry, it's been a long day. Of course I need to know current. I'm not entirely sure of the relationship between kVA and kW beyond that they're both measures of power. For example, in the following calculator 480kW is seen to be equivalent to 600kVA. What equation sits behind the buttons on...

Hi all. I'm a mechanical engineer by training and a manufacturing engineer by trade. I currently find myself in the position of being asked to fill out a spreadsheet containing, amongst other things, machine tools' power consumption in kVA. Occasionally an OEM will be helpful and provide...

I was assuming that the travel was parallel to the window, in which case my triangles method is good enough. If it were going into or away from the window, how would I go about it? I used to be pretty hot at transforming between different coordinate systems in 2d solid mechanics but dynamics...

As I was sitting at work the other day productively watching an aeroplane fly across the window I started to think of this problem. If I measure the time it takes for the image of the plane to track across a known distance on the window I can quickly calculate a speed at which the image is...

I was on an easyjet flight this morning and noticed a distinct and pronounced rattling, clicking noise coming from one of the engines. Not being a very good flier at the best of times (despite working in the aerospace sector) I was pretty worried. When the engines spooled up I was also sure I...

So one of my friends is buying a bicycle and I'm trying to convince her to plump for an aluminium model over some ridiculous 'retro' steel thing. I want to illustrate how aluminium allows for lighter structural members even taking into account the wider diameter tubes that ensure similar...

Does anyone know of an equation that models the build up of potential energy in an extension spring induced by twisting it when its motion is otherwise constrained in the transverse direction?

I know the steel-steel COF is about 0.8. Are the tribological properties of different steels, eg austenitic and 9%Cr, sufficiently different that this difference should be taken into account in the design of a component that will slide over two different steels, or sufficiently similar that the...

does anybody know a good definition of the above that does not include the words 'manufacturing' or 'system'? I'm tearing my hair out!

i just found this from a google search regarding tensors and index notation. it's very helpful, thanks.