Search results
Results from the WOW.Com Content Network
If the fluid is a liquid, a different type of limiting condition (also known as choked flow) occurs when the venturi effect acting on the liquid flow through the restriction causes a decrease of the liquid pressure beyond the restriction to below that of the liquid's vapor pressure at the prevailing liquid temperature.
The Venturi effect is named after its discoverer, the Italian physicist Giovanni Battista Venturi, and first published in 1797. The effect has various engineering applications, as the reduction in pressure inside the constriction can be used both for measuring the fluid flow and for moving other fluids (e.g. in a vacuum ejector).
Pressure has dimensions of energy per unit volume, therefore the pressure drop between two points must be proportional to the dynamic pressure q. We also know that pressure must be proportional to the length of the pipe between the two points L as the pressure drop per unit length is a constant.
A simplified version of the definition is: The k v factor of a valve indicates "The water flow in m 3 /h, at a pressure drop across the valve of 1 kgf/cm 2 when the valve is completely open. The complete definition also says that the flow medium must have a density of 1000 kg/m 3 and a kinematic viscosity of 10 −6 m 2 /s , e.g. water.
Pressure drop (Δp) Liquid-to-gas ratio (L/G) Liquid-inlet pressure (p L) Removal efficiency: Applications: Gases: 1.3–13 cm of water 7-13 L/m 3: 100-830 kPa 95% for very soluble gases Pulp and paper industry Chemical process industry Food industry Metals processing industry Particles: 0.5-5 in of water 50-100 gal/1,000 ft 3: 15-120 psig 1 ...
In a nozzle or other constriction, the discharge coefficient (also known as coefficient of discharge or efflux coefficient) is the ratio of the actual discharge to the ideal discharge, [1] i.e., the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an identical working fluid from the same initial conditions to the same exit pressures.
The Venturi flume consists of a flume with a constricted section in the center. By the Venturi effect, this causes a drop in the fluid pressure at the center of the constriction. By comparing the fluid pressure at the center of the flume with that earlier in the device, the rate of flow can be measured. [4] [5]
[1] [2] [3] A key question is the uniformity of the flow distribution and pressure drop. Fig. 1. Manifold arrangement for flow distribution. Traditionally, most of theoretical models are based on Bernoulli equation after taking the frictional losses into account using a control volume (Fig. 2).