Gilles
as allways, you are so clear. You make it sound obvious, whixh it is if
one thinks clearly :-)
Graham
Gilles Thesee wrote:
> <Gilles.Thesee@ac-grenoble.fr>
>
> Karel,
>
>>
>> I can not imagine that the presence of an oilthermostat changes the
>> flow of the cooling air trough the radiators.
>
>
> Of course not.
>
>> What do you really mean by taking in more air permanently?
>>
> Using a thermostat : change oil flow through the radiator, not air flow
>
> - Take in enough air to cool on the "worst case conditions", say
> ISA+23C and take-off power. This is a great amount of air.
> - Continuously flow it through the radiator. And so incur highest
> cooling drag permanently.
> - When you need less cooling (cruise, descent, cold day, etc.),
> prevent the oil from getting into the radiator. But still flow as much
> air through the radiator.
> - Add extra plumbing and obstruction in the oil circuit.
>
> Using a cowl flap : change airflow through radiator, not oil flow
>
> - Take in just enough air to cool the engine
> - Take in much air when on take-off on a hot day (highest cooling drag)
> - Take in less air during cruise (lower cooling drag)
> - Take in still less on a cold day or on descent (lowest possible
> cooling drag)
> - No disturbance in the oil circuit
>
> That's why the Mosquito and Mustang were so fast. Works great for us.
>
> Hope this helps,
> Best regards,
> Gilles
> http://contrails.free.fr
>
>
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