A movable plate of length l and width w in a gas moves into an infinite stationary plate at a velocity of u (Fig. P1.4). The movable plate is perforated to reduce the damping force. The plate gap, the pitch, and the size of the perforation are denoted by h, p, and f, respectively. Find an expression for the damping force F d in dimensionless form. If experiments show that the damping force is inversely proportional to the gap cubed, refine the expression.
