28-02-2015, 09:03 PM
i was asked to present a heat transfer topic in my class..
pls try helping me..
i need to present day after tomorrow...
even a 7-10 page ppt would serve the purpose..
thanks for considering my request
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aerodynamic heating ppt
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i was asked to present a heat transfer topic in my class..
pls try helping me..
i need to present day after tomorrow...
even a 7-10 page ppt would serve the purpose..
thanks for considering my request
11-04-2017, 12:56 PM
Aerodynamic heating is the heating of a solid body produced by its passage at high velocity through the air (or by passing air passed a test object in a wind tunnel), so that its kinetic energy is converted to heat By friction of the skin on the surface of the object at a rate that depends on the viscosity and velocity of the air. In science and engineering, it is more often a concern regarding meteorites, re-entry vehicles and the design of high-speed aircraft.
At high velocities through the air, the kinetic energy of the object is converted to heat through compression and friction. At lower speed, the object will lose heat to the air through which it passes, if the air is colder. The combined effect of the temperature of the air heat and the passage through it is called the stagnation temperature; The actual temperature is called the recovery temperature. These viscous dissipative effects on neighboring sub-layers cause the boundary layer to decelerate through a non-isentropic process. The heat then leads to the surface material from the higher temperature air. The result is an increase in material temperature and a loss of energy from the flow. Forced convection ensures that other materials replenish the gases that have cooled to continue the process.
Stagnation and recovery temperature of a flow increase with flow velocity and are higher at high speeds. The total thermal load of the object is a function of both the recovery temperature and the mass flow rate. Aerodynamic heating is higher at high speed and in the lower atmosphere where the density is higher. In addition to the convective process described above, there is also thermal radiation from the flow to the body and vice versa with the direction of the network established by the relative temperature of each.
The aerodynamic heating increases with the speed of the vehicle. Its effects are minimal at subsonic speeds but at supersonic speeds beyond M2.2 dictates the design / materials of the vehicle structure and internal systems. The heating effects are greater at the front edges but the entire vehicle is heated to a stabilized temperature if it remains at speed. Aerodynamic heating is treated by the use of high temperature alloys for metals, the addition of insulation from the exterior of the vehicle or the use of ablative material.
At high velocities through the air, the kinetic energy of the object is converted to heat through compression and friction. At lower speed, the object will lose heat to the air through which it passes, if the air is colder. The combined effect of the temperature of the air heat and the passage through it is called the stagnation temperature; The actual temperature is called the recovery temperature. These viscous dissipative effects on neighboring sub-layers cause the boundary layer to decelerate through a non-isentropic process. The heat then leads to the surface material from the higher temperature air. The result is an increase in material temperature and a loss of energy from the flow. Forced convection ensures that other materials replenish the gases that have cooled to continue the process.
Stagnation and recovery temperature of a flow increase with flow velocity and are higher at high speeds. The total thermal load of the object is a function of both the recovery temperature and the mass flow rate. Aerodynamic heating is higher at high speed and in the lower atmosphere where the density is higher. In addition to the convective process described above, there is also thermal radiation from the flow to the body and vice versa with the direction of the network established by the relative temperature of each.
The aerodynamic heating increases with the speed of the vehicle. Its effects are minimal at subsonic speeds but at supersonic speeds beyond M2.2 dictates the design / materials of the vehicle structure and internal systems. The heating effects are greater at the front edges but the entire vehicle is heated to a stabilized temperature if it remains at speed. Aerodynamic heating is treated by the use of high temperature alloys for metals, the addition of insulation from the exterior of the vehicle or the use of ablative material.
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