Compressible Definition and 80 Threads

G'day! This is my first post on this forum and I hope you find it usefull! Attached are complete set of Excel functions for *Isentropic Flow *Prandlt Meyer Expansion *Raleigh Flow *Fanno Flow *Plane Normal Shock *Plane Oblique Shock They are contained in the attached workbook (zipped as it...

Hi I was wondering, if a flow is compressible, then does that mean that if the inlet and exit of the control volume (same C.S. area) have different densities, would that mean that the temperature and/or pressure of the exit be different than at the inlet (assuming ideal gas)? If this were...

As a private study I'm trying to figure out fluid dynamics applied to compressed air systems. Most of the material I am studying considers only incompressible fluid flow. From what I understand about the differences between compressible and incompressible flow in terms of the equations it only...

Hi everyone, I am wondering if the heat equation is valid for compressible fluids like air. This is assuming constant 100% humidity. If it is not then how close is the appoximation. The model assumes that heat moves through an array of air only by conduction. At the moment I use a...

Suppose we have a flow of a fluid and let it flow (in x direction) into a stationary wall..the x velocity becomes zero...is this an example of stagnation point? If not, please cite an example of when that is true.

Homework Statement A compressor is required to drive acetylene gas at 1.85 kg/s through a horizontal pipe, 68.7 m long. The maximum pressure that may be developed by the compressor is to be found, and gas pressure at the delivery end of the pipeline must be 470 kPa. The system is to...

Hi, I'm new here so I'd like to apologise in advance if this has been posted before. I tried searching first but nothing came up. I'm doing a project on subsonic, compressible flow in curved ducts and have a question about the physics involved as the flow navigates a bend. Allow me to...

Hi, I'm trying to figure out the pressure exerted by a compressible gas (air) after it has expanded out of a cylinder for a simple conceptual design. I'm pretty sure that it's a simple problem, but I'm a little thickheaded atm. Here is my thinking so far: Due to the compressibility of air...

Homework Statement Consider the flow with velocity vector v = xi. Show that the individual particles have the position vectors r(t) = c1eti + c2j + c3k with constant c1, c2, c3. Show that the particles that at t = 0 are in the cube whose faces are portions of the planes x = 0, x = 1, y = 0, y...

Hi everyone, I did not get a reply in 3 weeks under mechanical engineeting... trying here. Here is practical question mixing compressible and none compressible fluids with a hydraulic press. Can the following actually work ? I believe it can but some experience people in this field looking...

I have read in different theorem's (Bernoulli's for example), that free air is considered incompressible below a speed of 0.4 Mach. If I were to place air in a jug and reuce the amount of space it occupies, then I am compressing it, but is this possible under certain conditions in free air?

Hi everyone, Here is practical question mixing compressible and none compressible fluids with a hydraulic press. Can the following actually work ? I believe it can but some experience people in this field looking at it may prove me wrong. Say we have a sphere, 1 cubic meter in volume. The...

Hi! I have experimental data measuring losses across an obstruction in compressible flow which basically consists of static pressure, total pressure and total temperature upstream of the obstruction and the same variables downstream for a number of different mass flow rates. This data was...

Hi, I'm currently a student and learning these two topics for a module. I've searched the net for many references but can't find anything that is really that helpful. Can anyone reference me any good links to questions and solutions regarding these topics? Also any books you guys would...

I have air flowing through a gate valve with lengths of pipe of matching diameter upstream and downstream. At a certain distance from the valve upstream and downstream, I am measuring static temperatures and static and stagnation pressures. I can estimate the Mach numbers at the tapping points...

I'm having trouble calculating the required pressure to get the desired volume flow rate (at outlet conditions). I'm no expert at compressible fluid systems, but I ended up being the one to design it... The system must feed helium vertically through 3/8" ID, 112 ft long tubing (ID can vary, I...

Hello I am a student working on at home project and I need help on choosing a compressible, soft material that works safely with wiring and electricity. The kind of material I need is something that is compressible and soft, sort of like a foam or gel heal pad that people put in their shoe. The...

Homework Statement I am currently studying for finals, and I am really confused about compressible flow in nozzles. Some questions I have: 1) What is exactly is the condition for choked flow for converging, diverging, and converging-diverging nozzles? 2) When can we assume that the back...

Hi, This is not homework but out of curiosity. On a diving board where are the points where stress is applied? Including shearing, compressible, and normal stress? Thanks

hii , i know the inlet conditions i.e. dia 2mm , pressure = 100 bar, density= 0.001176 m3/kg, mass flow rate remains constant= 0.09017 m/s , for same mass flow rate for pressure drop 80 bar(i.e. pressure at outlet is 20 bar) for COMPRESSIBLE FLUID what will be the outlet dia? take fluid carbon...

how to calculate head loss due to sudden enlargement in case of compressible fluid? hiiiiii guys, am graduate student, i want to know @ head loss in case of compressible fluid due to sudden enlargement...pls help me ...as soon as possible...

Hi all I am really confused with what is the actual meaning of compressible and incompressible flow?

Hi Guys, I know that the compressible Euler Equations are: \partial_t (\rho \mathbf u) + (\mathbf u \cdot \nabla)(\rho \mathbf u) + \nabla p = 0 \partial_t \rho + \nabla \cdot (\rho \mathbf u) = 0 Subject to suitable initial conditions and solving for \mathbf u, \; \rho unknown...

Hello, I'm doing the simulation by using the CFD Fluent. The reactor is 10 cm diameter and 1 m height. There is the water inlet (15mm) tangentially to the wall at the bottom end to produce the upward vortex flow. and the air-bubble injection axially at the middle of bottom end. The...

Homework Statement Starting from the equations of conservation of mass and momentum for an inviscid compressible gas, \frac{\partial \rho}{\partial t} + \bigtriangledown . (\rho {\bf u}) = 0 \rho ( \frac{\partial {\bf u}}{\partial t} + ({\bf u}. \bigtriangledown){\bf u}) = \bigtriangledown...

Do anyone know about any website were the Bernoulli equation is developed from the Newton Second law and without the assumption of steady state and incompressible fluid? With differential calculus, please. My textbook just give out the equations for unsteady state and incompressible, but I...

What are the governing equations for compressible fluid flow? Specifically; methane gas inlet pressure of 25 psi through a 3/8" dia. pipe and I need to relate this to a methane flow of 392,000 BTU/ hr @ 55-60psi 59 F and RH 60% (i.e. ISO 2314) through an as yet undetermined diameter pipe...

Hi guys: I am wondering with issue regarding high speed (subsonic) compressible air flow thorugh a pipe exit to atmosphere. So here is detail: Air coming from a reservoir and flowing thorugh an adiabatic constant area pipe and exit to atmosphere at the end of the pipe. Due to high...

Hi, I am new to physicsforums, and have no higher education in math or physics; but have much interest. I do not think I understand correctly the relationships described under the 'deal gas law' PV=nRT. Specifically, my question is: If pressure and temperature are directly proportional...

Hello, I need the Navier Stokes equations for compressible flow (Newtonian fluid would be ok) in cylinder coordinates. Can anybody help? Thanks