Does Aluminum Foil Really Prevent Burning on a Turkey in the Oven?

[cepheid]

My question pertains to mechanisms for heat transfer in an everyday situation. I've put that sentence first (rather than the next one) so that people looking at the post preview wouldn't think I was posting irrelevant threads. In Canada, today is Thanksgiving day. The packaging on my Turkey stated that certain parts of the turkey should be covered with aluminum foil in order to prevent burning (as well as to keep the juices in, I think). I understand how aluminum foil would prevent radiative heat transfer to those areas by reflecting IR radiation. I guess what I'm wondering is, what about heat transfer by conduction? At first I thought that metal, being a good thermal conductor, would conduct heat more efficiently into the turkey. Then it occurred to me that perhaps conducting heat from air --> turkey is in fact more efficient than having to conduct heat from air --> metal foil --> turkey. I asked one of my colleagues to weigh in with his opinion, and he seemed to think that it wouldn't matter because radiation is by far the dominant mechanism of heat transfer in a conventional oven. Is this true? I mean, I know of the "perfectly absorbing oven" construct used when developing the theoretical idea of a perfect blackbody. I'm just surprised that heat transfer from the interior of the oven to the turkey by some other mechanism wouldn't also matter.

 

[Bob_for_short]

Covering prevents drying out and burning.

Covering with aluminum preserves heat transfer rate.

Apart from radiative heat transfer, I think the convection is also an important mechanism.

 

[astrokreng]

I can confirm that heat transfer in an oven is primarily dominated by radiation. This is because conventional ovens operate at relatively low temperatures (usually below 500 degrees Fahrenheit), which is not high enough for significant heat conduction to occur. Therefore, using aluminum foil to reflect infrared radiation and prevent burning is an effective method for controlling the temperature of the turkey.

However, it is important to note that heat conduction can still occur in the oven, especially in areas where the turkey is in direct contact with the oven walls or racks. In this case, the metal foil may act as a barrier and prevent direct contact between the turkey and the oven, reducing the amount of heat transferred through conduction.

Additionally, covering certain parts of the turkey with aluminum foil can also help to keep the juices in, as you mentioned. This is because the foil acts as a barrier to prevent the escape of steam and moisture from the turkey, keeping it moist and preventing it from drying out.

In conclusion, while radiation is the dominant mechanism of heat transfer in a conventional oven, heat conduction can still occur and the use of aluminum foil can help to control it. So, it is a valid precaution to cover certain parts of the turkey with foil to prevent burning and retain moisture. Happy Thanksgiving!