In this lab we measured the pressure over the surface of a 1:12 scale model of a Dodge Charger. Then we used this data to determine how the force of pressure would affect the drag on the car. If there is a high pressure on the front of the car and a low pressure behind the car then the car will have a net force backwards that it will have to overcome.
The coefficient of pressure is a dimensionless parameter defined as Cp = (p - p_∞) / (1/2 * ρ * V²), where p is the static pressure at the pressure tap and p_∞ is the free-stream static pressure. The Cp value will be the same for objects of the same shape regardless of the size or the velocity of the air. This means we can say that our Cp values for the model should be the same as the Cp values on the full size Charger.