[ARCHIVED THREAD] - More Physics Fail (Page 1 of 2)
Posted: 1/6/2010 5:30:01 AM EDT
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Just heard an "expert" on KRMG (Tulsa radio) advise everyone to park their cars with the engine
facing away from the wind to protect it from the windchill temperatures tonight. 
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Just heard an "expert" on KRMG (Tulsa radio) advise everyone to park their cars with the engine facing away from the wind to protect it from the windchill temperatures tonight. Yup! Way too many are scientifically illiterate. Ironically, the left, which would claim to be a champion of science, would likely make it worse by removing it from schools in favor of propaganda. |
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Sure, windchill won't affect your engine. But, a nice cold wind blowing through your radiator will sure as hell cool down your engine a lot faster than not. Whether the engine cools to ambient temperature in 3 hours or 5 doesn't really matter. Once it hits ambient, it isn't going any further. Sure, plunging a hot engine in liquid nitrogen might not be a good idea, but a 30 MPH wind isn't going to have that effect. |
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Just heard an "expert" on KRMG (Tulsa radio) advise everyone to park their cars with the engine facing away from the wind to protect it from the windchill temperatures tonight. Yup! Way too many are scientifically illiterate. Ironically, the left, which would claim to be a champion of science, would likely make it worse by removing it from schools in favor of propaganda. get your science out of this thread! it hurts my feelings and doesn't feel right. 
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Quoted: Wind chill only affects oiving things. Or so I was told. This is my understanding and I'm curious for more authoritative confirmation, but, as a specific number below ambient, wind chill is a settled upon formula meant to determine what living things would perceive, being that the body temperature is above ambient, and wind, humidity and sweat cause convective, conductive, and evaporative cooling effects, thus speeding removal of heat from the skin. These same mechanisms can speed cooling of inanimate objects, and make something that is producing heat have to use more energy to maintain a temperature above ambient, but it doesn't actually cause them to drop in temperature below ambient or to the wind chill value. In other words, the radio guy is full of shit, unless you're only leaving your car parked for a short period and are hoping it doesn't cool to ambient before you return to it. |
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Quoted: Quoted: Yeah, those truck drivers who put covers over their radiators are idiots.  Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. |
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Quoted: Quoted: Quoted: Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. Except OTR drivers use the covers to keep and maintain engine temp while driving, or to attempt to maintain temps while parked. A cold diesel engine isn't going to significantly warm up at idle in these temps anyway, cover or no, in my experience. |
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Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. You are correct. But this only matters if the truck is running. Wind chill will not take inanimate objects below ambient air temperature so parking a vehicle facing away from the wind is usless. |
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Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. You are correct. But this only matters if the truck is running. Wind chill will not take inanimate objects below ambient air temperature so parking a vehicle facing away from the wind is usless. Wind chill won't take live objects below ambient air temp either. So the wind chill comparison isn't that far off of a description. |
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Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. You are correct. But this only matters if the truck is running. Wind chill will not take inanimate objects below ambient air temperature so parking a vehicle facing away from the wind is usless. But it may warm up faster facing away from the wind... |
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Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. Different application, the radio station is implying that it helps a car PARKED OVERNIGHT. The DJ clearly believes that 'wind chill' is capable of dropping temperature below what the thermometer reads. |
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Quoted: Quoted: Quoted: Quoted: Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. Except OTR drivers use the covers to keep and maintain engine temp while driving, or to attempt to maintain temps while parked. A cold diesel engine isn't going to significantly warm up at idle in these temps anyway, cover or no, in my experience. not to mention keeps the truck from over heating due to the radiator freezing up. |
| If it’s really cold, there is a strong wind, and you need to stop for thirty minutes, then it would be a good idea to park with your radiator out of the wind. The car’s engine will retain heat better that way. But if you are parking overnight then it won’t make any real difference. |
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The DJ clearly believes that 'wind chill' is capable of dropping temperature below what the thermostat reads. I should have been more clear - it wasn't the DJ, it was some guy who is like the manager of an automotive place or something. The DJ was Joe Kelley and he seems like an OK guy - conservative and likes guns. Someone should invite him to this thread. |
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Quoted: Quoted: Yeah, those truck drivers who put covers over their radiators are idiots. Comprehension fail. More BTU processing ability due to higher airflow is not the same as windchill. Really? It is called heat transfer and wind chill is due to an increase in the convection mode of heat transfer. Radiator as used in automotive applications is actually a convector. Specifically a compact water to air heat exchanger dominated by FORCED convection. But then again, I am probably explaining this to people that think the automotive cooling system's thermostat is a Boolean device, either closed or open (it is a proportional device, opening is proportional to temperature of the coolant flowing through it). And most vehicles don't need any cooling fan above 20 MPH. |
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Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. Would Idle RPM at sit still vs. running RPM at speed make a difference? |
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Quoted: Quoted: Quoted: Quoted: Quoted: Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. You are correct. But this only matters if the truck is running. Wind chill will not take inanimate objects below ambient air temperature so parking a vehicle facing away from the wind is usless. But it may warm up faster facing away from the wind... Well, you guys are both wrong and right. Windchill is basically a term that explains a wind current removing the built up micro-atmosphere that surrounds any object that is not the same temperature as the ambient temp. When an object such as the human skin is at a higher temperature than the ambient temperature, it heats the air around it. This is the micro-atmosphere, and it serves as a first means of insulation. It is also what keeps haired animals warm, as the hair efficiently traps a larger amount of the heated air, and makes it more difficult for wind currents to remove/replace. Same thing with our clothing. The clothing is not keeping you warm, it is just preventing the surrounding air from removing (or affecting, in the cases of high quality insulation) your bodies' own atmosphere. When you see temperatures reported at 20, and then the 'Windchill Factor' says it feels like 5 degrees, it's actually a load of bull. The windchill factor just means you actually FEEL that 20 degree temperature. It is *not* truly that cold. Unless you're wet or sweating, then all bets are off It works precisely the same with non organic objects also. If your engine is protected from the wind the air it heats up forms a barrier against the ambient air, and the engine will heat more rapidly than if a wind is blowing into it. This occurs with or without the radiator or coolant flowing, though the radiator accelerates the heat transfer process. So, while the engine will eventually still reach the same temperature, it will rise to a higher temperature at a faster pace if it is shielded from the wind. |
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Quoted: Quoted: Quoted: Quoted: Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. Would Idle RPM at sit still vs. running RPM at speed make a difference? If it has an electric fan, certainly. Electric fans only operate when the coolant is hotter than design specifications. The idle car not moving would then most likely have the fan off. But the moving car will have forced draft through the radiator. |
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A pretty over-the-top example of what passes for facts with the public.
Our education system has failed to produce citizens with enough knowledge to be productive in today's environment. I was taught Newtonian physics in college rather than Quantum theory, I gather because the professors at my school were not smart enough to teach Quantum. There's no excuse for teaching 80 year old science. |
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Wind chill won't take live objects below ambient air temp either. So the wind chill comparison isn't that far off of a description. However, the "live objects" in question are humans. And humans will kick the bucket if their body reaches ambient temperature on a nice spring day. So, windchill won't take human temperatures below ambient [1], but will take human temperatures below survivability. If your car engine would go kaput if its core temperature dropped below 94F and it had to keep running to maintain a normal temperature of 98F, the the wind speed would be a factor. Since the engine in a car parked overnight will not experience hypothermia, the wind is irrelevant. [1] Not really true for temperatures above 99F or so. But we are talking about cold temps so I will ignore that for the moment. |
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Quoted: A pretty over-the-top example of what passes for facts with the public. Our education system has failed to produce citizens with enough knowledge to be productive in today's environment. I was taught Newtonian physics in college rather than Quantum theory, I gather because the professors at my school were not smart enough to teach Quantum. There's no excuse for teaching 80 year old science. At the risk of exposing my ignorance, is Newtonian physics invalid? ETA - isn't quantum physics older than 80? |
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This thread is physics fail.
Engines have these thingies called thermostats that isolate the engine from the radiator until it warms up. The engine warms up in the same amount of time facing the wind or facing away. Yes, wind chill refers to perceived (as in by a human) temperature, but more wind increases convective heat transfer for any object, whether it sweats or not, so wind is relevant. However in this case it just means the engine will cool to ~ambient temp faster. Parking in any direction doesn't matter because 9 hours later when you go to work in the morning, the engine will be effectively ambient temperature. |
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This thread is physics fail. Engines have these thingies called thermostats that isolate the engine from the radiator until it warms up. The engine warms up in the same amount of time facing the wind or facing away. Yes, wind chill refers to perceived (as in by a human) temperature, but more wind increases convective heat transfer for any object, whether it sweats or not, so wind is relevant. However in this case it just means the engine will cool to ~ambient temp faster. Parking in any direction doesn't matter because 9 hours later when you go to work in the morning, the engine will be effectively ambient temperature. Again, until you start it up in the morning.... It will warm up faster facing away from the wind... Miss that part? |
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Just heard an "expert" on KRMG (Tulsa radio) advise everyone to park their cars with the engine facing away from the wind to protect it from the windchill temperatures tonight. Maybe he thinks the water will freeze,if only there were some type of anti freezing agent you could mix with the water 
But the windchill (aka the "feels like factor") is particularly hard on inanimate objects. |
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At the risk of exposing my ignorance, is Newtonian physics invalid? No just crude and outdated. Newton is like algebra where Quantum physics is like calculus to steal a mathematics comparison. There's nothing outdated about it. Classical mechanics is just as relevant now as when the apple fell. Nobody designs guns or 99% of mechanical devices trying to take into account relative motion, QM, etc.. because the added accuracy it provides makes no difference whatsoever. |
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This thread is physics fail. Engines have these thingies called thermostats that isolate the engine from the radiator until it warms up. The engine warms up in the same amount of time facing the wind or facing away. Yes, wind chill refers to perceived (as in by a human) temperature, but more wind increases convective heat transfer for any object, whether it sweats or not, so wind is relevant. However in this case it just means the engine will cool to ~ambient temp faster. Parking in any direction doesn't matter because 9 hours later when you go to work in the morning, the engine will be effectively ambient temperature. Again, until you start it up in the morning.... It will warm up faster facing away from the wind... Miss that part? 
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Yeah, those truck drivers who put covers over their radiators are idiots. Those are for when the truck is running and/or moving so wind chill is taking heat away from the radiator, then. The cover reduces the rate. The radiator doesn't know the difference between the truck standing still in a 30 MPH wind and the truck moving 30 MPH in calm air. The net effect is cold air moving across the cooling tubes, removing heat. You are correct. But this only matters if the truck is running. Wind chill will not take inanimate objects below ambient air temperature so parking a vehicle facing away from the wind is usless. But it may warm up faster facing away from the wind... Well, you guys are both wrong and right. Windchill is basically a term that explains a wind current removing the built up micro-atmosphere that surrounds any object that is not the same temperature as the ambient temp. When an object such as the human skin is at a higher temperature than the ambient temperature, it heats the air around it. This is the micro-atmosphere, and it serves as a first means of insulation. It is also what keeps haired animals warm, as the hair efficiently traps a larger amount of the heated air, and makes it more difficult for wind currents to remove/replace. Same thing with our clothing. The clothing is not keeping you warm, it is just preventing the surrounding air from removing (or affecting, in the cases of high quality insulation) your bodies' own atmosphere. When you see temperatures reported at 20, and then the 'Windchill Factor' says it feels like 5 degrees, it's actually a load of bull. The windchill factor just means you actually FEEL that 20 degree temperature. It is *not* truly that cold. Unless you're wet or sweating, then all bets are off
It works precisely the same with non organic objects also. If your engine is protected from the wind the air it heats up forms a barrier against the ambient air, and the engine will heat more rapidly than if a wind is blowing into it. This occurs with or without the radiator or coolant flowing, though the radiator accelerates the heat transfer process. So, while the engine will eventually still reach the same temperature, it will rise to a higher temperature at a faster pace if it is shielded from the wind. I know how wind chill works on animals. Same principle as why you wear a wet suit in the water, to warm a layer of water next to your body. I believe the radio person believed that if you park your car headed into the wind, it would be colder in the AM than if it was facing away which is untrue. You are correct that it would warm up (marginally) faster if wind protected. |
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This thread is physics fail. Engines have these thingies called thermostats that isolate the engine from the radiator until it warms up. The engine warms up in the same amount of time facing the wind or facing away. Yes, wind chill refers to perceived (as in by a human) temperature, but more wind increases convective heat transfer for any object, whether it sweats or not, so wind is relevant. However in this case it just means the engine will cool to ~ambient temp faster. Parking in any direction doesn't matter because 9 hours later when you go to work in the morning, the engine will be effectively ambient temperature. Again, until you start it up in the morning.... It will warm up faster facing away from the wind... Miss that part? There is still wind circulating over the outside of the engine block, regardless of the state of the thermostat. |
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A pretty over-the-top example of what passes for facts with the public. Our education system has failed to produce citizens with enough knowledge to be productive in today's environment. I was taught Newtonian physics in college rather than Quantum theory, I gather because the professors at my school were not smart enough to teach Quantum. There's no excuse for teaching 80 year old science. Talk about hitting the nail on the head. |
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Different application, the radio station is implying that it helps a car PARKED OVERNIGHT. The DJ clearly believes that 'wind chill' is capable of dropping temperature below what the thermometer reads. A passenger in my car once asked if driving at a higher speed would cause erroneous readings on the outside temp display since there was more air flowing over the sensor. This guy is a mechanical engineer, too. I figured it was safer to just ::faceplam:: than bitchslap him since I was the one doing the driving at the time. |
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This thread is physics fail. Engines have these thingies called thermostats that isolate the engine from the radiator until it warms up. The engine warms up in the same amount of time facing the wind or facing away. Yes, wind chill refers to perceived (as in by a human) temperature, but more wind increases convective heat transfer for any object, whether it sweats or not, so wind is relevant. However in this case it just means the engine will cool to ~ambient temp faster. Parking in any direction doesn't matter because 9 hours later when you go to work in the morning, the engine will be effectively ambient temperature. Again, until you start it up in the morning.... It will warm up faster facing away from the wind... Miss that part? There is still wind circulating over the outside of the engine block, regardless of the state of the thermostat.
And if I park with the hood facing a white wall, the radiant heat will be reflected back increasing my warm up time by .01 seconds. 
An idling car engine is pumping out thousands of joules per second to heat up a X00 pound chunk of aluminum and steel, the increase in heat transfer from eddies swirling around the engine doesn't amount to squat. |
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A pretty over-the-top example of what passes for facts with the public. Our education system has failed to produce citizens with enough knowledge to be productive in today's environment. I was taught Newtonian physics in college rather than Quantum theory, I gather because the professors at my school were not smart enough to teach Quantum. There's no excuse for teaching 80 year old science. Talk about hitting the nail on the head. Yeah, because as evident here, people didn't even learn basic physics in school. So let's teach them Quantum Mechanics! That will make them "productive in today's environment"! |