Search results
Results from the WOW.Com Content Network
where is the heat capacity ratio / of the gas and where is the total (stagnation) upstream pressure. For air with a heat capacity ratio =, then =; other gases have in the range 1.09 (e.g. butane) to 1.67 (monatomic gases), so the critical pressure ratio varies in the range < / <, which means that, depending on the gas, choked flow usually ...
Convergent nozzles are used on many jet engines. If the nozzle pressure ratio is above the critical value (about 1.8:1) a convergent nozzle will choke, resulting in some of the expansion to atmospheric pressure taking place downstream of the throat (i.e., smallest flow area), in the jet wake. Although jet momentum still produces much of the ...
Convergent nozzles accelerate subsonic fluids. If the nozzle pressure ratio is high enough, then the flow will reach sonic velocity at the narrowest point (i.e. the nozzle throat). In this situation, the nozzle is said to be choked. Increasing the nozzle pressure ratio further will not increase the throat Mach number above one.
The pressure ratios for the design flow rate at the intake and outlet are = / and = /, and the off-design ratios are = / and = /. If the speed of sound is reached in a stage, the group of stages can be analyzed until that stage, which is the last in the group, with the remaining stages forming another group of analysis.
As the pressure is reduced still further, a pressure is reached that result in M = 1 at the throat with subsonic flow throughout the remainder of the nozzle. There is another receiver pressure substantially below that of curve C that also results in isentropic flow throughout the nozzle, represented by curve D; after the throat the flow is ...
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.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
single-expansion ramp nozzle (SERN), a linear expansion nozzle, where the gas pressure transfers work only on one side and which could be described as a single-sided aerospike nozzle. Each of these allows the supersonic flow to adapt to the ambient pressure by expanding or contracting, thereby changing the exit ratio so that it is at (or near ...