This question relates to drag coefficients and the drag force. This should be very easy, but I cannot find a reference that gives the formula for Frontal Area (Fa) for a square cylinder (i.e., a box). On one hand, it should be as simple as Length * Height of the windward face (where the length...
Oh, I embarrased as I have found my mistake. I entered 10^-12 watts into Excel as 10e-12. This is a pitfall I have somehow always had a mental block on, and it is returning to haunt me here. 10^-12 = 1e-12 <> 10e-12.
Sorry...thanks all for understanding.
While the ideal loudspeaker emits a sphere of sound, many people picture the typical loudspeaker as emitting a cone of sound. But, I am trying to model outdoor mass notification systems, such as tornado warning systems. These look like a stack of pancakes on a pole and can emit 360 degrees in...
My reference, by noted authorities Don and Carolyn Davis, claim there are two methods to find dB-PWL (sometimes called Lw). I find the methods differ by 10dB. What's up?
(Ref: "Sound System Engineering", 1st ed, 12th printing 1986, p.40)
a) Lw = 10 log (watts/watts ref)
b) Lw = 10 log (watts)...
MechTools, thanks for the reply. I recognize that is rather basic, so I had to rethink what is puzzling me. So, let me re-phrase the question: Is the following correct?
For something banded to a pole, there will be a reaction force equal and opposite to the load it is supporting. So, when...
It's been awhile, so can someone confirm my thinking? It is common to strap auxillary items (like an antenna mount) to a pole. As such, the moment arm would be the sum of (a) the distance the mount is offset from the pole + (b) the pole diameter? ...or pole radius?
My instict says to use the...
JStephen, I appreciate this advice. However, I do not have access to ASCE# 7, although I have seen exerpts onlne. It is an excellent reference.
Also, I know that applying the fluid mechanics method is an oversimplified approach, geared for an academic exercise...not for professional practice...
Trying to determine wind load on a smoke stack, I have read many a (fluid mechanics) text that only seem to address wind sheer. Some evaluate this wind sheer force as a drag force, and others use a similar approach - only without a drag coefficient in the (very similar) equation. So, which is...
