Evaluate the concepts of fluid mechanics and their relevance to mechanical engineering. Discuss the fundamental properties of fluids, including viscosity, density, and pressure, and their behavior under different flow conditions. Analyze the governing equations of fluid flow, such as the Navier-Stokes equations, and the various simplifications and assumptions used in practical fluid mechanics analyses. Additionally, explore the applications of fluid mechanics in engineering design, ranging from pipe flow and turbomachinery to aerodynamics and hydraulic systems.