Question to Mxmanic

writes:

Air does not behave very much like an imcompressible fluid at low air
speeds. Not even close.

That's not what the engineers say.

Under some conditions, low air speeds is one of them, air can be
treated like it is an imcompressible fluid.

The difference between TAS and EAS is only about 13% even at Mach 1. Since
small aircraft come nowhere near to Mach 1, for all practical purposes air is
incompressible for most calculations.

Obviously air, being a gas, can be compressed, but taking that into account at
low speeds greatly complicates the calculations, and the final result isn't
significantly different.

--
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In rec.aviation.piloting Mxsmanic wrote:
writes:

Air does not behave very much like an imcompressible fluid at low air
speeds. Not even close.

That's not what the engineers say.

I am an engineer and have the degree to prove it and I totally agree
with him, so stuff it.

Under some conditions, low air speeds is one of them, air can be
treated like it is an imcompressible fluid.

The difference between TAS and EAS is only about 13% even at Mach 1. Since
small aircraft come nowhere near to Mach 1, for all practical purposes air is
incompressible for most calculations.

Word salad that shows you don't get the concept.

At low airspeed, the equations for incompressible fluid flow are close
enough to what actually happens that they can be used for practical
calculations.

This does not mean that air "acts like an incompressible fluid" in any
way, shape, or form.

Obviously air, being a gas, can be compressed, but taking that into account at
low speeds greatly complicates the calculations, and the final result isn't
significantly different.

Finally, the light comes on...

Well, gee-whiz, you backed into a place where you are finally correct.

Aren't you great?

--
Jim Pennino

Remove .spam.sux to reply.

writes:

I am an engineer and have the degree to prove it and I totally agree
with him, so stuff it.

I'm actually the King of England.

Finally, the light comes on...

The light was always on, but it's hard to see through heavily tinted glasses.

--
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Wrong again, Anthony! There is no King of England.

Rip

Mxsmanic wrote:
writes:

I am an engineer and have the degree to prove it and I totally agree
with him, so stuff it.

I'm actually the King of England.

Finally, the light comes on...

The light was always on, but it's hard to see through heavily tinted glasses.

Mxsmanic wrote in
:

That's not what the engineers say.

Name 3.

On Apr 17, 5:09 pm, Mxsmanic wrote:
writes:
Air does not behave very much like an imcompressible fluid at low air
speeds. Not even close.

That's not what the engineers say.

Maybe only the ones that drives locomotives.


Under some conditions, low air speeds is one of them, air can be
treated like it is an imcompressible fluid.



Obviously air, being a gas, can be compressed, but taking that into account at
low speeds greatly complicates the calculations, and the final result isn't
significantly different.


Duh.


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writes:

Duh.

The clock on your aircraft runs slower as you accelerate, due to relativistic
effects. But then it also runs faster as you climb, again due to relativistic
effects. Do you take these effects into account in your on-board
calculations?

[And while they may be trivial for aircraft, they are not in all cases--the
GPS has to be adjusted for these effects to maintain accuracy, for example.]

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It is not acceleration. It is speed. GPS travels much faster than we do. I
doubt we have clocks accurate enough to measure the relativistic effects at
our speeds.

And climbing has nothing to do with relativity.

mike

"Mxsmanic" wrote in message
...
writes:

Duh.

The clock on your aircraft runs slower as you accelerate, due to
relativistic
effects. But then it also runs faster as you climb, again due to
relativistic
effects. Do you take these effects into account in your on-board
calculations?

[And while they may be trivial for aircraft, they are not in all
cases--the
GPS has to be adjusted for these effects to maintain accuracy, for
example.]

--
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mike regish writes:

It is not acceleration. It is speed. GPS travels much faster than we do.

No. There are nearly half a dozen relativistic effects that must be
compensated for in the GPS. The nominal clock frequencies, for example, must
be adjusted by slightly less than one part in two billion in order to adjust
for the cumulative relativistic effects.

I doubt we have clocks accurate enough to measure the relativistic effects at
our speeds.

Sure you do ... in your GPS receivers. The adjustments for relativistic
effects are necessary to make the receivers reasonably accurate.

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"Mxsmanic" wrote in message
...
mike regish writes:

It is not acceleration. It is speed. GPS travels much faster than we do.

No. There are nearly half a dozen relativistic effects that must be
compensated for in the GPS. The nominal clock frequencies, for example,
must
be adjusted by slightly less than one part in two billion in order to
adjust
for the cumulative relativistic effects.

I doubt we have clocks accurate enough to measure the relativistic
effects at
our speeds.

Sure you do ... in your GPS receivers. The adjustments for relativistic
effects are necessary to make the receivers reasonably accurate.


Wow! That's useful information!