First off, can a human even be roasted?
Why, yes they can be.
The most notorious way of it is by the means of a Brazen Bull. An instrument of torture from ancient Greece, the Bull was made of bronze and hollow. Men were placed inside and a fire was set underneath the device until it heated up and roasted the victims inside. The Brazen Bull’s inventor, Perillos, rigged the Bull so a man’s screams sounded like the braying of a bull.
People did die this way, or in a similar device such as a coffin made of brass, and there’s tales of the scorched bones shining like jewels and being turned in bracelets. The catch is that it took hours for the person inside to die. And, judging by all that movies and books have taught me, dragons don’t spew fire continuously for 10 minutes, let alone several hours.
But the Brazen Bull was made of bronze, whose melting point is about 1,742 degrees Fahrenheit. Medieval armor is made of steel or iron. Different types of steel have different melting points, but one of the lowest melts at 1,333 degrees Fahrenheit. Iron on the other hand melts at 2,800 degrees Fahrenheit. Human flesh starts to burn at 140 degrees Fahrenheit.And how hot is dragon fire? I’m going to guess 2,200 degrees Fahrenheit, as that’s the temperature of orange fire, the most common color I’ve seen in movies. Which means dragon fire is more than hot enough to melt steel armor. But even the hottest fire, which burns a dazzling white, is still a hundred degrees cooler than the melting point of iron.But we don’t have to melt armor, just burn the person inside. And since a candle flame is hot enough to do that, you can bet a dragon can. So yes, logically, a dragon can roast a human.Can he do it in one breath?Let’s say a dragon spits fire for 40 sec. He hits the knight dead in the chest, who’s wearing steel armor that weighs 42.64 kg. The average body surface area of an adult is 1.73 meters squared, and for simplicity’s sake lets say the armor is of even thickness, so he’s covered by .003 meters of steel. Or 0.12 inches if that’s easier for you to see.
Doing a bunch of chemistry (in which I relayed on friends, please please correct this if you think it’s wrong) I determined the heat transfer of dragon fire to an armor plate is 284 (using 60 C [140 F] as the final temp and a refreshing mountain temp of 4.4 C as the initial air/armor temp). And from there I figured it would take about 5 seconds the armor to be hot enough to burn.And how long does he take to cook?Not much more than a minute. So, a 40 second burst won’t completely kill a knight, but to a dragon who likes them raw, it probably won’t mind. And after the first five seconds, when the knight is burned, he’ll be in too much pain to move anyway.
But, if your dragon can only produce short bits of flame, say for 5 seconds, he’ll only burn the knight and he can then proceed to roll around the try to stab its heart. Slightly burns probably won’t deter a knight in the heat of battle, but they can add up. So eventually the knight would make a mistake due to pain and be killed.
Either way, dragons will come out the victor most of the time.
(Note number 2: Humans supposedly taste like pork, and since dragons usually eat sheep (not lambs) I wonder if they prefer mutton and only eat us when there's no other option. Or if we're just in front of them. Kinda how like if there's a bag of chips in front of me, I will eat them all.
Also, Blogger is being a poopy head and not allowing me to put a caption on my image. It's by dA user ElegantArtist21 and is used with permission.)