why temperature drops when wind blows? ie. commercial jet exterior is very cold despite flying over equator.?

Question

in a hot, enclosed, stuffy room, the temperature could be lowered simply by turning on the fan and not window. why? thanks.

Answer 1

has to do with physical property of moving air. Moving air removes or allows for evaporation of heat from an object.. (why outside temperature is always chillier when wind blows)

Answer 2

You feel warm and stuffy because the water from your body (sweat) is not evaporating and you feel stuffy and hot. When the window is opened, if there is no breeze, the cooling effect is marginal, but with the fan switched on, the rate of evaporation improves considerably and you feel cool. The heat needed for evaporation is absorbed by the water from your body and so you feel cool. However, if the windows are closed, the room does become stuffy even with the fan on.

The jet flies at a very high altitude and the air temperature is sub zero, so when it lands, it is still cold.

Answer 3

Its a thermodynamic principle called total temperature derived from enthalpy. If you can imagine, that there is no energy being added to the system, therefore the "dynamic" temperature + "static" temperature = total temperature. Think of it like this, the temperature of the air upstream cannot be increased, since no energy is being added. Therefore, you must feel a relative decrease in static temperature when you are moving or the air is moving past you.

Ignoring the Work, Heat and Potential Energy terms, we have:

H = h + v^2/2

where: H is the Stagnation (or Total) Enthalpy
h is the Static Enthalpy
v is the Velocity

Substituting for temperature, we have:
T = t + v^2/(2*cp)

where: cp is the Specific Heat at Constant Pressure
T is the Stagnation (or Total) Temperature
t is the Static Temperature

The "t" is what you feel. One of the previous answerers noted something about the leading edges heating up on aircraft, that temperature is the "T".

Answer 4

Hi. The jet is flying in a greatly reduced atmospheric pressure with ambient temperatures often in the -40 F range. It's not the wind but Boyle's law. The fan in a stuffy room allows perspiration to evaporate from you, cooling a person. The thermometer does not change.

Answer 5

in your example tha altitude has a lot to do with it as well, it's colder at 30,000ft than it is at sea level....but the answer is much like why a fan makes you cooler inside your house.

any to materials that come into contact with eachother try to equalise ther temperature with one anouther, even air, the jet would grow colder in cool air, but since it's moving forward or ( or in your living room the air is moving in relation to you,) quite simply there is more material coming in contact,

example you have a cubic foot of air at 50deg F and your 98deg F
in stagnant air the the air will raise to say 70deg F around you and you drop to say 97deg F......however if every second the air is replaced by 50deg F air the the delta or difference in the temerature stays greater to more heat is transfered to the cooler air.

in a plane it's say 70, the air is I don't know say 0 if it sat still the air around the plane would warm up to 50 and the plane would cool to 50, if the air is replaces continulally with air that is zero the plane over time will cool to zero outside.

alos in regards to a stuffy room, the walls and floor are cooler than other parts, any air movement that will transfer heat to the coolest area of the room will take temperature away from the surrounding areas.

Answer 6

wrong....jet exterior gets hot when flying fast concord skin was hot enough to cook eggs on.....stealth bombers skin wasnt sealed untill skin got hot & expanded...

wind chill factor is created in part by evaporation of moisture about 1 degree for every 10 mph...

altitude has something to do with it as well 10,000 feet is cold even in hot air balloon....