Any idea what happens to flame in micro Gravity?
We all have seen a candle burn bright. But have we ever put to thought why the flame burns in that particular way? The answer is something we all have felt since our birth. It is what keeps us glued to this earth. It has it's effect on anything and everything on this earth, from a tiny fish in the deepest part of ocean to the aircraft flying above us. Yes, its Earth's Gravity.
Gravity has a hidden role in the composition and formation of a flame. First let us look into how a flame burns. The flame heats the air around it and makes it less dense, the gravity pulls down the comparatively cooler and oxygen-rich air thereby pushing the hot air upwards. This process makes the flame shoot up.
In space, combustion is impossible as no oxygen is present. Inside a spacecraft, the air mixture is same as that on earth, but the gravity is millions of times weaker. In micro-gravity, the upward lift is not present and oxygen is drawn into the flame using a different phenomena. As the flame is fed by slow diffusion, effectively the entire surface of the flame is the "bottom", reacting with the fresh air close to the fuel. Thus the flame is spherical like a fireball. As CO2 cannot leave the combustion area, as easily as on earth, the outward diffusion limits the inward diffusion of oxygen. When a candle burns, it is being consumed molecule by molecule. But in micro-gravity carbon strings do not get burned and thus the flame is blue, cooler and much dimmer.
Gravity has a hidden role in the composition and formation of a flame. First let us look into how a flame burns. The flame heats the air around it and makes it less dense, the gravity pulls down the comparatively cooler and oxygen-rich air thereby pushing the hot air upwards. This process makes the flame shoot up.
In space, combustion is impossible as no oxygen is present. Inside a spacecraft, the air mixture is same as that on earth, but the gravity is millions of times weaker. In micro-gravity, the upward lift is not present and oxygen is drawn into the flame using a different phenomena. As the flame is fed by slow diffusion, effectively the entire surface of the flame is the "bottom", reacting with the fresh air close to the fuel. Thus the flame is spherical like a fireball. As CO2 cannot leave the combustion area, as easily as on earth, the outward diffusion limits the inward diffusion of oxygen. When a candle burns, it is being consumed molecule by molecule. But in micro-gravity carbon strings do not get burned and thus the flame is blue, cooler and much dimmer.
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