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For air flow at room temperature, when the outlet pressure is less than 1/2 the absolute inlet pressure, the flow becomes quite simple (although it reaches sonic velocity internally). With C v = 1.0 and 200 psia inlet pressure, the flow is 100 standard cubic feet per minute (scfm).
Atmospheric air pressure is directly related to altitude, temperature, and composition. [1] In engineering, airflow is a measurement of the amount of air per unit of time that flows through a particular device. It can be described as a volumetric flow rate (volume of air per unit time) or a mass flow rate (mass of air per unit time). What ...
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.
In hypersonic flow, the pressure coefficient can be accurately calculated for a vehicle using Newton's corpuscular theory of fluid motion, which is inaccurate for low-speed flow and relies on three assumptions: [5] The flow can be modeled as a stream of particles in rectilinear motion; Upon impact with a surface, all normal momentum is lost
An arc would sometimes take place in a long irregular path rather than at the minimal distance between the electrodes. For example, in air, at a pressure of one atmosphere, the distance for minimal breakdown voltage is about 7.5 μm. The voltage required to arc this distance is 327 V, which is insufficient to ignite the arcs for gaps that are ...
Most charts or tables indicate the type of friction factor, or at least provide the formula for the friction factor with laminar flow. If the formula for laminar flow is f = 16 / Re , it is the Fanning factor f, and if the formula for laminar flow is f D = 64 / Re , it is the Darcy–Weisbach factor f D.
Air changes per hour, abbreviated ACPH or ACH, or air change rate is the number of times that the total air volume in a room or space is completely removed and replaced in an hour. If the air in the space is either uniform or perfectly mixed, air changes per hour is a measure of how many times the air within a defined space is replaced each hour.
In aerodynamics, the normal shock tables are a series of tabulated data listing the various properties before and after the occurrence of a normal shock wave. [1] With a given upstream Mach number , the post-shock Mach number can be calculated along with the pressure , density , temperature , and stagnation pressure ratios.