Pressure Energy, Resistance and Reactance in Fluid Leak & Flow

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The fluid current in a fluid circuit, corresponding to the electrical current in an electrical circuit, is determined by a fluid pressure corresponding to electrical pressure (voltage), and a fluid impedance corresponding to electrical impedance, and directly proportional to the fluid pressure and inversely proportional to the fluid impedance between two ends of the fluid circuit. The fluid impedance is the algebraic sum of the fluid resistance and the fluid reactance between the two ends. Fluid resistance is a physical quantity for measuring the peripheral resistance of a fluid current; fluid reactance, a physical quantity for measuring the front resistance of a fluid current; and leak resistance, a physical quantity for measuring the tightness of a seal. The three quantities have an identical measuring unit, indicating the sustained fluid pressure needed for a unit of fluid currents, or for a unit cubage of fluids for a unit of time, to flow through a fluid resistance, a fluid reactance or a leak resistance, and so (the current) x (the resistance) = (the pressure energy consumed by the resistance), (the current) x (the reactance) = (the pressure energy converted into the kinetic energy by the reactance), (the current) x (the leak resistance) = (the pressure energy consumed by the leak resistance), and (the current) x (the resistance + the reactance) = (the general pressure needed for a fluid current to flow through a fluid circuit). A leak path of seals, almost with kinetic energy negligible, can be considered a typical fluid circuit without any fluid reactance. Reactance of piping is from its each bore-changing passage or port. Reactance from reducing passages or ports is positive, and reactance from enlarging passages or ports is negative. A fluid current flowing past a moving object is equivalent to the one flowing in a pipe's wall-bulged passage whose corresponding right inclusion body has the same axis, generatrix and volume as the object's has. The fluid currents flowing over and under a wing are equivalent to the ones flowing in two parallel contiguous pipe lengths that are placed one under the other and use the length of the wing chord plane as the circumference of their cylindrical inlet and outlet walls, and use the upper and lower average curve surfaces of the wing separately as their upper and lower curve walls. The lift of the wing is from the inner pressure difference of the two pipe lengths.