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FM/DM threads Everything about FM/DM in CoD

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  #51  
Old 07-13-2012, 02:51 AM
Seadog Seadog is offline
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Originally Posted by Crumpp View Post
Wow.........



You guys really believe England meets standard atmospheric conditions for most of the day in August 1940??? Even with the temperature of 15C and 1013Mb?
Manston:
1940 7 19.9 11.8 --- 56.9 (mean daily temp = 15.9C)

What ground temperature would a Luftwaffe raid, arriving over Manston at 8am in mid July 1940, be likely to find?


What ground temperature would they likely encounter over the English Channel?

I have provided the mean high and lows for various locations, and it is pretty obvious that 15C or lower ground temp is a distinct possibility for any likely location, especially before noon, and in the Late (daylight) afternoon (say after 7pm).

Last edited by Seadog; 07-13-2012 at 02:58 AM.
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  #52  
Old 07-13-2012, 03:42 AM
IvanK IvanK is offline
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You think England in August has RH = 0???

Come on all you pilots!!!

Goodie Goodie More abbreviations in an attempt to bamboozle the masses.
RH for what its worth is relative Humidity.

As it is I am pretty sure the CLOD atmospheric model doesn't even model "Humidity" per see.
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  #53  
Old 07-13-2012, 04:31 AM
MiG-3U MiG-3U is offline
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Well, argument on summertime conditions is pretty much pointless.

The FTH depends on pressure altitude so at summertime conditions the FTH for given manifold pressure actually increases in the density altitude scale. In other words, the full 12lbs boost in summertime conditions is available at higher density altitude than at standard conditions.

Physical explanation is fairly simple: The supercharger increases the density in manifolds by keeping the pressure constant up to the FTH. In summertime the warmer air is less dense than in standard conditions so given manifold pressure gives less power than at standard conditions. However, the ability of the supercharger to keep the pressure depends on pressure difference between manifolds and outside atmoshere (plus dynamic pressure) and in summertime the pressure at given density altitude is higher than in standard conditions, hence the FTH increases in the density altitude scale while staying constant at the pressure altitude scale.

All this can be found from the USAF Flight Test Engineering Handbook, available from Scribd:

http://www.scribd.com/doc/19204672/U...ering-Handbook

The problem here is that some members have stated something else and they can't never admit that they were wrong...
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  #54  
Old 07-13-2012, 05:19 AM
NZtyphoon NZtyphoon is offline
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Originally Posted by Crumpp View Post
Wow.........



You guys really believe England meets standard atmospheric conditions for most of the day in August 1940??? Even with the temperature of 15C and 1013Mb?
The usual story, Crumpp thinks he's an expert on British weather conditions during the Battle of Britain, when it has been very carefully explained to him that conditions can be so variable. Flying in Britain - or NZ for that matter - is very different from flying in mid-West America, for very good reasons.

Has Crumpp got any detailed figures for Britain's atmospheric temperatures and pressures at different altitudes during Summer 1940?
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  #55  
Old 07-13-2012, 10:43 AM
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Crumpp Crumpp is offline
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Quote:
argument on summertime conditions
In August??



Quote:
As it is I am pretty sure the CLOD atmospheric model doesn't even model "Humidity" per see.
Probably not and completely irrelevant to the conditions of the Battle of Britain.
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  #56  
Old 07-13-2012, 11:35 AM
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Crumpp Crumpp is offline
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Quote:
All this can be found from the USAF Flight Test Engineering Handbook, available from Scribd
Look guy,

The charts are in pressure altitude because the aircraft data is in pressure altitude.

The temperature correction is the density correction.

An engine sees density altitude and your FTH will reflect.

That is not being a "know it all". It is just how it works.
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  #57  
Old 07-13-2012, 11:36 AM
NZtyphoon NZtyphoon is offline
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Originally Posted by Crumpp View Post
In August??

Why Crumpp has decided to pick on August alone is anyone's guess, but its typical of an attempt to pretend that he knows British weather patterns in 1940 better than anyone else.

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Originally Posted by Crumpp View Post
Probably not and completely irrelevant to the conditions of the Battle of Britain.
As are most of Crumpp's speculative arguments...
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  #58  
Old 07-13-2012, 11:49 AM
ATAG_Dutch ATAG_Dutch is offline
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Originally Posted by NZtyphoon View Post
Why Crumpp has decided to pick on August alone is anyone's guess, but its typical of an attempt to pretend that he knows British weather patterns in 1940 better than anyone else.
If you chaps want a really good laugh for a change, just take a look at the current 'British Summertime Weather Patterns'.

Makes me want to emigrate somewhere nice and dry, such as Burma, or the Amazon basin.

Sorry for OT.
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  #59  
Old 07-13-2012, 12:05 PM
NZtyphoon NZtyphoon is offline
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If you chaps want a really good laugh for a change, just take a look at the current 'British Summertime Weather Patterns'.

Makes me want to emigrate somewhere nice and dry, such as Burma, or the Amazon basin.

Sorry for OT.
Yes, 'tis Bit of a worry for the Olympics. All the best for London, hope the weather behaves!
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  #60  
Old 07-13-2012, 01:02 PM
TomcatViP TomcatViP is offline
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Quote:
Originally Posted by ATAG_Dutch View Post
... or the Amazon basin.

Sorry for OT.
Do you mean the basin of an ... ?
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