Why does flame from a gas stove/burner curve inward as it goes up (i.e. forming a waterdrop shape)?

Question

Why does flame from a gas stove/burner curve inward as it goes up (i.e. forming a waterdrop shape)?

Answer 1

Well, it looked like a couple of the answers almost had it...

The reason the gas comes together is a combination of reasons, by primarily due to convection.  Hot air /gas rises, making a vaccuum drawing in more air from the sides.

Air coming in from the sides pushes the gas closer together as it rises making it bend inward, more and more as it goes upward.

A burner, such as on a gas stove is a straight drilled hole, usually pointing to the side. Some burners already point upwards, so you can't tell, but for the ones pointing to the side you will notice that the higher the pressure, (As you turn the flame from low to medium to high,) the further out the jet of flame reaches, before starting to bend upwards due to convection.  This tells you it is not the shape of the pipe or the hole it comes out of that has anything to do with the flame shape.  (Since the holes are straight drill holes, the flame would come straight out, if it were not for convection.)

Answer 2

The burning gas is part of a convection current similar to the flame of a candle (ignoring how the burner holes may direct the discharge of the gas).  As a candle burns hot air rises and is replaced by cooler (fresh) air from below.  The cool air expands (like in a hot air balloon) and has buoyancy (like a bubble in water).  Not only does the buoyancy direct the hot air upwards but it accelerates moving faster and stretching out.  This causes the 'bulb' of hot air to curve inward to a tip and upward as a smaller column of hot gas.  It would be similar to pulling taffy into a string from a ball of taffy.

Answer 3

I dont knoe but I found your question interesting, just as the flame of a candle is tear shaped?

Answer 4

What you see as a flame is the fluorescence of very hot gas.  At the base of a gas flame, there is a blue cone where the gas and air mixture has not ignited.  Just above the cone is an extremely bright bit where the chemical reaction is taking place.  The gas around this is extremely hot and gives off light.  You see it as a flame.

If you were in zero gravity, the heat would go outwards in all directions and the flame would be a globe.  Gravity means that heat rises so there's more hot gas above the chemical reaction than at the sides.  That makes the visible bit hemispherical at the bottom but rising to a point at the top.

Answer 5

Because the air that is entrained with the gas is passing through a very small o*****e, and forms this shape as it leaves the o*****e. as the air flows around the gas.The air is pushing out and the hot gas is rising, a mixture of the two.forms this shape.