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The atmosphere of Mars has been losing mass to space since the planet's core slowed down, and the leakage of gases still continues today. [ 4 ] [ 8 ] [ 9 ] The atmosphere of Mars is colder than Earth’s owing to the larger distance from the Sun, receiving less solar energy and has a lower effective temperature , which is about 210 K (−63 °C ...
convection of hot gas flow past the surface of the body and catalytic chemical recombination reactions between the surface and atmospheric gases; and; radiation from the energetic shock layer that forms in the front and sides of the body [15] As velocity increases, both convective and radiative heating increase, but at different rates.
Mars atmospheric entry is the entry into the atmosphere of Mars. High velocity entry into Martian air creates a CO 2 -N 2 plasma, as opposed to O 2 -N 2 for Earth air. [ 1 ] Mars entry is affected by the radiative effects of hot CO 2 gas and Martian dust suspended in the air. [ 2 ]
The heat transfer coefficient is often calculated from the Nusselt number (a dimensionless number). There are also online calculators available specifically for Heat-transfer fluid applications. Experimental assessment of the heat transfer coefficient poses some challenges especially when small fluxes are to be measured (e.g. < 0.2 W/cm 2). [1] [2]
Convection (or convective heat transfer) is the transfer of heat from one place to another due to the movement of fluid. Although often discussed as a distinct method of heat transfer, convective heat transfer involves the combined processes of conduction (heat diffusion) and advection (heat transfer by bulk fluid flow ).
The law holds well for forced air and pumped liquid cooling, where the fluid velocity does not rise with increasing temperature difference. Newton's law is most closely obeyed in purely conduction-type cooling. However, the heat transfer coefficient is a function of the temperature difference in natural convective (buoyancy driven) heat transfer.
Atmospheric convection is called "deep" when it extends from near the surface to above the 500 hPa level, generally stopping at the tropopause at around 200 hPa. [ citation needed ] Most atmospheric deep convection occurs in the tropics as the rising branch of the Hadley circulation and represents a strong local coupling between the surface and ...
All convective processes also move heat partly by diffusion, as well. The flow of fluid may be forced by external processes, or sometimes (in gravitational fields) by buoyancy forces caused when thermal energy expands the fluid (for example in a fire plume), thus influencing its own transfer. The latter process is often called "natural convection".