![Examples of Max QRockets, aircraft, missiles, and other vehicles are all designed to withstand only a certain maximum q before they will suffer structural damage, so the term is used throughout aerospace engineering and not just by NASA.During a normal Space Shuttle launch, for example, max Q is at an altitude of around 11 km (35,000 ft).[1] During a typical Apollo mission, max Q occurred approximately between 13 km and 14 km of altitude (43,000–46,000 ft).[2][3]The point of max Q is a key milestone during a rocket launch, because that is the point at which the airframe undergoes the most mechanical stress. The Space Shuttle Challenger disintegrated shortly after max Q.](https://image.slidesharecdn.com/maxq-100219023840-phpapp02/85/Max-Q-5-320.jpg)
![Dynamic Pressure In incompressible fluid dynamicsdynamic pressure (indicated with q, or Q, and sometimes called velocity pressure or impact pressure) is the quantity defined by:[1]where (using SI units):= dynamic pressure in pascals, = fluid density in kg/m3 (e.g. density of air), = fluid velocity in m/s.](https://image.slidesharecdn.com/maxq-100219023840-phpapp02/85/Max-Q-6-320.jpg)
![Further on DynamicMany authors define dynamic pressure only for incompressible flows. (For compressible flows, these authors use the concept of impact pressure.) However, some British authors extend their definition of dynamic pressure to include compressible flows.[2][3]If the fluid in question can be considered an ideal gas (which is generally the case for air), the dynamic pressure can be expressed as a function of fluid pressure and Mach number.By applying the ideal gas law:[4]the definition of speed of sound and of Mach number :[5] and dynamic pressure can be rewritten as:[6]where (using SI units):= static pressure in pascals, = density in kg.m−3, = specific gas constant (287.05 J.kg−1.K−1 for air), = absolute temperature in degrees kelvin, = Mach number (non-dimensional), = ratio of specific heats (non-dimensional) (1.4 for air at sea level conditions), = fluid velocity in m.s−1, = speed of sound in m.s−1](https://image.slidesharecdn.com/maxq-100219023840-phpapp02/85/Max-Q-7-320.jpg)
Max Q
- 1. Max QMathematical view of Max Q
- 2. What is Max Q?In aerospace engineering, max Q is the point of maximum dynamic pressure, the point at which aerodynamic stress on a spacecraft in atmospheric flight is maximized.
- 3. The FormulaConsidering the definition of dynamic pressure: q = ρ v² / 2, where q is the amount of aerodynamic pressure, ρ (rho) is the air density and v is the vehicle speed, we have that such quantity: is zero at lift-off, when the air density ρ is high but the vehicle's speed v=0is zero outside the atmosphere, where the speed v is high but the air density ρ=0is always positive (or zero, as above) given the quantities involved
- 4. Will there always be a point of Max Q? Therefore, as explained in the formula there will necessarily be a point where the dynamic pressure is maximum: that point is precisely max Q.In other words, below the max Q point, the effect of the spacecraft acceleration overcomes the decrease in density as to create more dynamic pressure (opposing kinetic energy) acting on the craft. Above the max Q point, the opposite is true, and the dynamic pressure acting against the craft decreases as the air density decreases, ultimately reaching a Q of 0 where the air density is zero.
- 5. Examples of Max QRockets, aircraft, missiles, and other vehicles are all designed to withstand only a certain maximum q before they will suffer structural damage, so the term is used throughout aerospace engineering and not just by NASA.During a normal Space Shuttle launch, for example, max Q is at an altitude of around 11 km (35,000 ft).[1] During a typical Apollo mission, max Q occurred approximately between 13 km and 14 km of altitude (43,000–46,000 ft).[2][3]The point of max Q is a key milestone during a rocket launch, because that is the point at which the airframe undergoes the most mechanical stress. The Space Shuttle Challenger disintegrated shortly after max Q.
- 6. Dynamic Pressure In incompressible fluid dynamicsdynamic pressure (indicated with q, or Q, and sometimes called velocity pressure or impact pressure) is the quantity defined by:[1]where (using SI units):= dynamic pressure in pascals, = fluid density in kg/m3 (e.g. density of air), = fluid velocity in m/s.
- 7. Further on DynamicMany authors define dynamic pressure only for incompressible flows. (For compressible flows, these authors use the concept of impact pressure.) However, some British authors extend their definition of dynamic pressure to include compressible flows.[2][3]If the fluid in question can be considered an ideal gas (which is generally the case for air), the dynamic pressure can be expressed as a function of fluid pressure and Mach number.By applying the ideal gas law:[4]the definition of speed of sound and of Mach number :[5] and dynamic pressure can be rewritten as:[6]where (using SI units):= static pressure in pascals, = density in kg.m−3, = specific gas constant (287.05 J.kg−1.K−1 for air), = absolute temperature in degrees kelvin, = Mach number (non-dimensional), = ratio of specific heats (non-dimensional) (1.4 for air at sea level conditions), = fluid velocity in m.s−1, = speed of sound in m.s−1
- 8. ConclusionThis may seem complex however the ideals of this theory were figured out by simple pilots. As many of our early astronauts learned their vehicles tended to break apart at the point of MAX Q or Dynamic Pressure. This is a simple overview I made for you to help you understand the area physics behind it.