Bernoulli's Equation Bernoulli's equation is a special case of the general energy equation that is probably the most widely-used tool for solving fluid flow problems. It provides an easy way to relate the elevation head, velocity head, and pressure head of a fluid. Learn the Bernoulli equation for ideal fluids, its components, and how to use it in fluid mechanics problems. See the proof, diagrams, and solved examples of Bernoulli’s principle in physics. Bernoulli's Principle, formulated by Daniel Bernoulli and later expressed as Bernoulli's Equation by Leonhard Euler in 1752, is a fundamental concept in fluid mechanics. It describes the relationship between the pressure (P), velocity, and height (h) of a fluid in motion. Bernoulli's equation along the streamline that begins far upstream of the tube and comes to rest in the mouth of the Pitot tube shows the Pitot tube measures the stagnation pressure in the flow. Therefore, to find the velocity V_e, we need to know the density of air, and the pressure difference (p_0 - p_e).