6. Fluid Motion and Mechanical Vibration

This chapter will demonstrate the fluid motion and mechanical vibration of product. When airplane is in taxi, take-off or landing, a variety of functions such as airframe, wings, fuselage, engine, control, etc. are required. Especially, fluid mechanics is the critical area that studies the effect of forces on fluid motion. Due to fluid motion, they might be repetitively subjected to (random) loads and make problems—fracture or vibration. To withstand their own loads in airplane, mechanical structures like wing are designed to have proper stiffness and strength. If not, airplane will abruptly cause some problems in flight. To experimentally assess the structural effects of fluid force, engineers should understand the basic concepts of fluid mechanics—viscosity, boundary layer, etc. And we also will discuss the mechanical vibration which happens when system is applied by undesired force—imbalances in the rotating parts or the movement of a tire on a gravel road. Unless isolated by proper stiffness design, system will create unwanted sound or waste energy. Ultimately mechanical system will fracture. To prevent it, engineers might find and correct the design faults of mechanical products. Therefore, parametric ALT might be a kind of engineering solutions.