NCEES Fundamentals of Engineering (FE) Mechanical Practice Exam

The Bernoulli equation for fluid flow is based on the principle of conservation of energy. This principle states that the total mechanical energy in a fluid system remains constant if no energy is added or removed. In the context of fluid flow, this means that the sum of the kinetic energy, potential energy, and pressure energy per unit volume remains constant along a streamlined flow path.

The Bernoulli equation mathematically expresses this relationship, connecting the velocity of the fluid, the elevation height above a reference point, and the pressure within the fluid. As the speed of the fluid increases, the pressure decreases, and if the fluid elevation increases, the pressure changes accordingly. This energy balance allows engineers to analyze and predict the behavior of fluid systems, such as in pipe flow, airfoil lift, and various hydraulic applications.

The other principles mentioned, like conservation of mass, form the basis for the continuity equation, which deals with the flow rate of incompressible fluids but does not account for energy changes. The conservation of momentum principle leads to different equations and approaches, focusing more on forces rather than energy transformations, which does not directly relate to Bernoulli’s conclusion.