Flow Definition and 1000 Threads

I have this little doubt because in class, the professor said the work is equal to the integrate of vdP, but i don't know how to prove it, why it isn't PdV like those exercises in a cylinder-piston

Why does current not split into the middle junction? I notice that this is true regardless of the values of the resistors.

I was reading an article and it mentioned that surface roughness can affect boundary layer transition? How? I am just a casual reader of aerodynamics but have a background in engineering can anyone explain the physics behind surface roughness affecting boundary layers and flow separation? and...

Rayleigh flow refers to frictionless, non-adiabatic flow through a constant area duct where the effect of heat addition or rejection is considered. Consider the case of air traveling through a heat exchanger: The air travels through the duct and picks up heat from the surface of the heat...

What happens when electrons flow in two opposite directions in an electrical circuit?

I'm trying to find how the author finds the boundary condition at ##r\to\infty## is ## \Phi(r,\theta, \phi) = - V r cos \theta##. Using the spherical coordinates. ##- V \hat{z} = \nabla \Phi## ##- V ( cos \theta \hat{r} - sin \theta \hat{\theta}) = \frac{d \Phi}{dr}\hat{r} + 1/r \frac{d...

These are probably a stupid questions. For Couette planar flow with horizontal infinite length plates, the top one moving with a constant velocity in the horizontal direction, with a single layer, one assumes there is only velocity in the horizontal direction. 1)In the case of Couette...

I’m not at all sure I’m posting this in the right forum. If not, please forgive me. Also, I have no background in physics. That said, here goes: If 2bar of helium flowing through a 9.0mm inner diameter tube yields a flow rate of 15 liters per minute, what bar would one need to yield an...

Hi, I know people here have been super helpful in resolving DYI projects I posted. I'm just going out on a limb, upping the ante a notch a little, I know. Does anyone know anyone that might be capable of troubleshooting/fix a C6 flow cytometer like the one in the image? I've been using it so...

Image from Wiley Intro Physics Textbook sample problem This was the given problem. In the diagram, one can see that the current flowing into each battery equals the current flowing out of each battery. Is this always the case, and why? If there was only one battery, I guess it could be...

Hello everybody, I am thinking of the following problem: A sphere a radius r is in a much larger container of radius R. In this container, a fluid continuously flows with turbulent conditions from bottom to top. I would like to approximate the force pushing the sphere up. Some calculations I...

How does a free surface flow cause non-linearity , is it through the boundary conditions ? Which one and how ? Thanks

If a gas flowing through a tube would meet two orifices with different diameters in the same cross section, how much of the gas would flow through each orifice and what would the gas velocity be in dependence of orifice diameter?

By substituting the darcy-weisbach equation into darcy’s law we get q = -kf/µL * (L/D) * (𝜌V^2/2) This can be further simplified by substituting the equation for friction factor for laminar flow, f = 64/Re , with the equation for reynolds number, Re = ρVD/µ substituted in such that: q =...

I'm trying to figure out how describe the mass of air between the piston face and the und of the tube ( position ##o##) in the acompanying diagram. At ##t = 0##, the mass of air in the tube is ##M_o##, and the system is static with tube length ##l##. The ##x## coordinate describes how far...

If you have 2 pipes of the same cross sectional area, same volume of fluid, and same length, the only difference is one pipe is coiled several times over a cylindrical object theoretically shortening the length of the pipe, while the other is a straight pipe. Will the flow rate be same in both...

In a recent thread, I thought I understood what was going on but alas, I am still confused. So I offer this diagram and ask for more help please. Shown is an aircraft holding pattern. The one on the left is flown in still air. The one on the right is flown with a wind coming from the...

Hello everyone; Please need some help to check if my calculation are correct (and if possible some explantation) Bernoulli's equation between point 1 and 3 is given by: P_1+1/2 ρv_1^2 + ρgh_1 = P_3+1/2 ρv_3^2 + ρgh_3 P_1 = P_(atm ) v_1= 0 m/s h_1= 0.875 m P_3 = P_(atm ) v_3= ? m/s h_3= 0...

My AC has begun to emit a rather foul smell, which has led me to geek out on the inner workings of its indoor section. For example, how does the condensed moisture make its way to the drain pan? I am assuming that the condensation happens on the fins of the evaporator. But in that case, what...

I can imagine the experiment: the pressure at the surface will drop while the tank is emptying (if no air bubbles enter through the evacuation of course, otherwise it restores the pressure atm at the surface). The flow speed decreases as a function of time until the external pressure maintains a...

Consider a fluid flow with density ##\rho=\rho(t,x)## and velocity vector ##v=v(t,x)##. Assume it satisfies the continuity equation $$ \partial_t \rho + \nabla \cdot (\rho v) = 0. $$ We now that, by Reynolds Transport Theorem (RTT), this implies that the total mass is conserved $$...

For this problem, The mains water pressure at the council tubby (just before it enters a house) is of the order of 1.5 bar. Using Poiseuille equation, estimate the flow rate in a typical home at the kitchen tap. You will need to make reasonable estimates on several parameters, clearly state...

Hello everyone. First post! I am struggling to understand an issue in our (histology) lab. We use large downdraft tables which extract the noxious substances we use, mainly formaldehyde, while we process surgical samples. These tables have a steel cover with lots of holes about 5mm diameter...

In the last chapter of Schutz devoted to Cosmology, Schutz writes So it seems that in 1985 it was assumed as obvious that the recession speed could not exceed ##c##. The consensus seems to have swiftly changed. When did that happen? Was it debated at all?

For a fluid that is confined to a finite region with no sources and sinks, are the only options for the flow field a) static, and b) cyclic? The example I have in mind is Rayleigh convection in a shallow dish heated from below, where convection cells are formed beyond a certain temperature...

Picture below can someone please explain me why will the water come out of faucet with the pressure of 2000 Pa? I was expecting the answer to be "water will not come out thrugh the faucet because the pressure from the barrel is not strong enough to overcome the height of the pipe" since...

Is it possible to create (nearly?) laminar flow in a tube with rectangular C.S. , around 1 cm X 5 cm , with air moving at around 100 to 150 m/sec? Turbulence will likely set in sooner or later, but can the laminar flow be made to last over say 20 cm?

I am a high school student trying to carry out an experiment about fluid. Thus I am studying Knudsen flow and come up with following questions. 1. How can a Knudsen flow occurs? 2. Can I simply dig a small hole on a board and make Knudsen flow? 3. What the difference between viscous flow...

I have tried to approach in the following way I am stuck. How should I approach this next.please help

I want to start with two scenarios and both contains a blower and a tunnel fitting for the blower and both have almost the same diameter. The tunnel has s little higher so that the blower can be fitted inside. In the first scenario, the blower is fitted at the end of the tunnel i.e. the flow...

Folks, I'm trying to formulate the stability problem in the incompressible inviscid limit and find the dispersion relation in the Couette flow regime. As shown, the 2 infinite plates move one against the other, unlike the "standard" case where one plate is static and the second moves. I'm trying...

I would like to know when a alternator is charging a battery is the current flow a series opposing circuit......?

Spacetime expands at an accelerated rate and the particles with movement associated to this expansion are coupled to the Hubble flow. In many papers that I've read, objects coupled to the Hubble flow are treated as if they have some velocity and kinetic energy associated with it.However, can...

Hey all, It is possible I am over complicating this, but is the flow in and out of a hydraulic motor with an electrical load the same? Assuming no losses. Scenario is a hydraulic piston (moving by some external force), driving a bi-directional hydraulic motor which itself is driving an electric...

App.js: import React from 'react' import Helloworld from './components/HelloWorld'; import Users from "./components/Users"; const App = () => { return ( <div> <h1>List of Users</h1> <Users name="Zino Emi" job="Developer" /> <Users name="Lionel Messi" job="Web Developer"...

Hello, i’m not good in physics so I came here for help. I have a high pressured gas tank (200 bars) and a flow rate regulator. I need to release 15L of nitrogen per minute, but my regulator only measures output pressure between 0 and 400 bars (0 - 6000 psi). How do I measure the output pressure...

Promises syntax that I learnt: let p = new Promise(function (resolve, reject) { let x = 20, y = 20; if (x == y) { resolve(); } else { reject(); } })p.then(function () { console.log("that's correct"); }) .catch(function () { console.log("that's not correct"); }) I...

So far I have only been able to come up with an equation for the flow (Q) using the orifice equation through the inclined area and thus not dependent on the angle. Can someone help me with an expression for this?

Q：Please hlep me to understand which ans is correct.To determine the flow rate in Line AB. $$\mathrm{Known}：V_A,q,r_A = constant.$$ so/ select：## A,{B}^{\text{'}},B,A,## is control volume $${Q}_{AB}={Q}_{A{B}^{\text{'}}}=\iint _{A}^{}({V}_{A})dA={\int }_{{\theta }_{A}}^{{\theta...

Please help me to understand what wrong with method 2. ref.Flowrate Between Streamlines (Thank you for your time and consideration.)

I solved the case where m=0.99999. Then the height at which it overflows can be obtained with the equation, when points on the liquid surface are chosen. Then the cross-sectional area is given by the circumference of the circle times the height that the parabola reaches, that cross-sectional...

Greetings, I've come across lots of exercises regarding Bernoulli's equation. However, never seen one where the top of the vessel is closed, and fluid flow exists via gas (air) going in. Has this problem been studied in the past? Assume a cylindrical vessel filled to the maximum with a D-sized...

Hello, I am currently studiying Bernoulli's equation and I have trubble understanding something , say we have a horizontal hose (no change in altitude of pressure ) Bernoulli's equation state that an ideal fluid can flow thought the hose with the same velocity , does an ideal fluid need a...

Dear all, I'm currently working on a basic coating application and I'm struggling to get the flow rate stable. I'm trying to figure out how to calculate the theoretical flow rate in the application. The coating is stored in a pressure tank, which we put on an overpressure of 15psi. From the...

Hello! I have a question about aerodynamic drag. It sounds simple but when trying to understand why the relative velocity can be used in calculations I have some trouble. The formula is 0.5*rho*u2*cd*A where u is the relative velocity between the object and the fluid. The cd value depends on the...

Alright, this is more of a conceptual question than a HW question that will nonetheless help me design something. In the attached image, air is flowing through a large area tube and then a small area tube from right to left. A collaborator previously figured out the equation for measuring the...

Hello,i am just a college student who has a little confusion on when to consider both laminar and turbulent flow -say over a flat plate,should i assume turbulent flow all over the plate and use the related equations(nusselt number) or use the laminar and turbulent equation(Nusslet number) but if...

Attached formula can't figure out. H is 12 inches, Q is what I want to know, L is 40 feet, D is 18 inches, A I assume is area of 18 inches, g have no clue what this is. The Culver is 18" X 40 foot long coragated with water 1 foot over inlet and water on outlet 2" lower than culvert and the...

I have two related but separated questions: 1. If I have an open circuit connected to a battery, let's say an alkaline battery connected to a straight wire and nothing more, once I connect the battery to this wire there will be for a short time a current in the wire? Since in the battery due to...

I hope you all have a wonderful day, Some time ago, I bought a device that is supposed to eliminate static charge on my vinyl records (which aids to the overall sound quality). I was sitting on the couch and having a deep thought, as me myself have no professional background in physics, I...