Flow Definition and 1000 Threads

Homework Statement In a horizontal rectangular open channel 20 m wide the water depth is 9 m. When a smooth hump 1.5 m high is introduced in the channel floor, a drop of 1 m is produced in the water surface. What is the flow rate, neglecting energy losses? It is proposed to place a pier at the...

Hi, I have a question regarding the flow rate in a pipe. According to the general rule the flow rate is: Q = v * A where Q [m3/s] v [m/s] A [m2] So according to this formula the flow rate depends only on the inner area of the pipe and the velocity of the fluid and does...

Hello everyone, I have been trying to calculate some exhaust flow rates for a while, and I am having some issues here. I was wondering if anyone could provide any insight. I am making a few assumptions for this calculation. I am assuming no fuel or air is lost through blow by gasses into the...

Homework Statement Hello, I have really hard time to express the gas law PV=nRT to PQ=ṁRT where Q is volumetric flow rate and ṁ- mass flow rate. Is it possible ? Teacher told me, it is ... Homework EquationsThe Attempt at a Solution

Hi, I'm not sure if I'm posting in the right spot but I'm going to guess this is an easy question for you all. I'm going to give as much detail as I can, maybe too much.. My 2 family house condo has a single 2" or 3" water supply from the street. It is split to supply the first floor and...

My book says that for uniform rotational flow, the velocity at any point is proportional to r (v = wr.) In vortex flow, the velocity at any point is proportional to 1/r (angular momentum is conserved.) However, in uniform rotational flow, isn't angular momentum also conserved so the same logic...

Homework Statement [/B] (a) Show that for an incompressible flow the velocity potential satisfies ##\nabla^2 \phi = 0##. Show further the relation for the potential to be ## \frac{\partial \phi}{\partial t} + \frac{\nabla \phi \dot \nabla \phi}{2} + \frac{p}{\rho} + gz = const.## (b)Write out...

Hi evryone. My name is Lucian, I'm a Computer Engineer. I'm working in a project of a company to develop a flow meter using a microcontroller and Infrared sensors. I'm stuck in the mechanic fluid part. We're trying to develop this product basing in the mechanic model of the attached picture...

I'm designing a testing unit where I need to estimate the smallest diameter of a short complex pipe (around 1 meter, three bends and some diameter viariations). Since the pipe is being cooled down in a water bath after production, my idea is to force water with a known pressure in one end of the...

Hey guys, I'm doing a university project where I am designing the hvac system of a lab. I'm having trouble figuring out how I'm supposed to calculate the exhaust flow required through fume hoods.I know this depends on the type of hazard that is being dealt with in the Lab but my knowledge of the...

How can energy be transported in a hydraulic circuit? The volume of oil is nearly incompressible. Therefor energy can not be transported in the form of potential (inner) energy of the oil.

Dear all ! I am an engineer from Vietnam! I just started to work 4 months ago. Now I got assignments with compressed air system! The compressor is not mentioned here! We have an air vessel of 500 Liters, and pressure is 7 bar. Before air vessel is an air booster with inlet pressure of 6 bar. The...

Hi there, I wondered if someone with a good knowledge of medicine/human biology could help me - this may sound like a very silly question but I don't know enough about biology to know for sure! I am 25 weeks pregnant with twins and accidentally fell asleep with a hair tie around my wrist. When I...

so i was reading on some applications of bernoulli's principle and i encountered a paragraph in which it was stated that 'the speed of the flow of blood in this region ( the region inside the artery) is raised which lower the pressure inside the artery and it may collapse due to external...

I am interested in mass flow rate in conveyor screw transportation http://www.colormaxsystems.com/wp-content/uploads/2013/11/5-screws-300x222.jpg any recommended book,engineering guides ?

Dear Friends, Merry Christmas to All. I am pleased to join this forum of Physics Experts. Please I need some help to work on COMSOL, I am about to start learning COMSOL. I'm going to work on this topic ' Vanadium Redox Flow Battery ' (VRFB) and this topic has many physics so it can be...

OK, So I have been having an on and off debate with my family about this. I saw a pump at Home Depot that said it has a 30 ft head. Then it went on to show that the flow rate varied as the output of the pump changed in height. Now I thought that this was wrong. I just finished a course in...

Hello All. This is my first post, and I hope it is not too simplistic, but I am out of my normal line of work here. I am trying to understand the relationships between flow, velocity, and cross sectional area with gases and fluids(air and water). Imagine a large vertical, cylindrical tank...

< Mentor Note -- thread moved to HH from the technical engineering forums, so no HH Template is shown > Pics are attached, my concerns are with question 4 and 5. For q4 -which way is flow? How do we know? -the working then goes on to say that energy loss is compensated by increasing in...

I know how to calculate current flow across a resister from the voltage, but what about current flow into a battery? Do I need to put a resister in the system so that I know how much current is flowing, or does that drop the voltage to the battery too much? I'm guessing the battery has an...

Is it possible to calculate the max flow rate (gals/m) achievable through a given piping system with only the following variables? - 4" SDR 11 HDPE pipe (3.633" ID) - 28,000 feet of pipe from source to destination - 90' of elevation change from source to destination - destination is another...

Thinking of individual fluid particles, my guess is that the "force" is simply particles backing up somewhat at the constriction point and contributing a higher proportion of collisions on particles ahead of them in a direction down the pipe. As the average movement of the particles is directed...

I might be going crazy or searching at the wrong places. Is there an empirical formula for solving the hydrodynamic entry length of laminar flow through a circular annulus? Thanks!

In the following diagrams: and: Is current flowing horizontal or vertical&horizontal? I'm sure for the rectangle one the flow of current is horizontal, but not sure of that square.

In this time I try to search after information about 2 things: 1. the gas flow system in the car and the car exhaust 2. the materials that use in air pollution filters If you know good website / professor / paper / book / video lecture / other in one of this area so I will glad if you can let me...

Hello. I'm new to the forums. I apologize if I have posted this in the wrong topic area. I'm new to this hydrodynamics area and I'm trying to learn the concepts of boundary layer thicknesses. My question is about laminar pipe flow and calculating displacement and momentum thicknesses. I was...

I have a simple series circuit, with a 9V power supply, and a 1 ohm resistor. If I place to identical fuses in series on opposite sides of the resistor that are rated for <9A, which fuse will blow first? I am essentially asking if current flows identically through all points in a wire the...

Homework Statement Material is blown into cart A from cart B at a rate b kilograms per second. The material leaves the chute vertically down- ward, so that it has the same horizontal velocity u as cart B. At the moment of interest, cart A has mass M and velocity v. Find dv/dt, the instantaneous...

Hi I need to work out a flow rate of a fire hydrant in Liters per second. I know the pressure is 3.5bar and the pipe diameter is 100mm Any help would be appreciated Thanks

Homework Statement Recall that a flow line, c(t), of a vector field F has c'(t)=F(c(t)) at all times t. Show all work below. a.) Let c(t) be the flow line of a particle moving in a conservative force field F=-grad(f), where f:R^3->R, f(x,y,z) >=0 for all (x,y,z), represents the potential...

Hi everyone, I'm doing a simulation and need some help. A capillary which is closed on both ends with the length l (x=0 to x=l), with a radius R and the volume pi*R^2*l is dropped on a parachut at the time t=0 from a hight h above ground. At t=0 the pressure inside the capillary is p_i0 (this...

Hi there, I have a question about incompressible Stokes flow in a channel between solid walls (with no-slip boundary conditions at ##y = 0, L_y##). It is my intuition that, if the flow direction is ##x## (periodic), and the direction normal to the walls is ##y##, then there cannot be a net...

If I have a pump of 50psi and 2L/min flow rate and it is connected to a nozzle. The nozzle catalogue specs for example shows that : 40psi = 0.5L/min 50psi = 0.6L/min 60psi = 0.7L/min Is flow rate at the nozzle output 0.6L/min? Regardless of the pump flow rate, as long as pressure are same...

Hey guys, can some of ou help me with this question: I need to calculate the volumic flow rate for air by using the ideal gas law. Things i know from the assignment: molarmass = 28,96 kg/kmol Pressure = 1 bar mass flow = 2 kg/s t in = 20 degrees celcius t out = 50 degrees celcius (sorry for bad...

For a situation where we have two infinite flat parallel plates with a viscous fluid in between if the upper plate if acted upon by a constant force then the plate should accelerate. The fluid layer adjacently below the upper plate should have the same acceleration as this plate (due to no-slip...

So I learned recently that pressure gradient in the flow direction for flow over a flat plate is zero. However I don't understand this, because there has to be something that sets the flow in motion in the first place, and for fluids this has to be a pressure gradient. Could someone explain why...

does steam flow from top to bottom or bottom to top in a heat exchanger

I'm new here, and I have a question that might be easy but really confuses me. Does the volumetric flow rate of incompressible fluid change across a valve?. Based on my analysis, no it can not change since the mass is conserved, and since it's incompressible fluid. I know that the velocity will...

Hi, I'm trying to measure the steady state velocity field behind the wake of a bluff body in the wind tunnel. My uni is equipped with 4-hole cobra probes which is capable of receiving flow within a 45 degree cone of acceptance. As the base of a bluff body dominated with re-circulating flow...

I've noticed that certain propane torches will have a seemingly linear relationship between their PSI and BTU/hr. IE, 18 PSI -> 220,000 BTU/hr. From this a person could calculate how much gas is being burned per sec/minute/hr. So, is there a general relationship/formula that I can use to...

Hello everyone, I have a small question regarding mass and volume flow rates. It is shown in my book that there is a difference between path functions and point functions. I can understand why work or heat for example are path functions. However, I don't understand why mass transfer is also...

I am looking at air system that is under a constant pressure of 350 mbar into a pipe that has 40 - 2 mm round holes. Is there a formula that I can use to calculate the total volume of air nm3/hr that will escape the system? Let's just say the air temp is constant. Can anyone help with this?

At work we have a shed in full sun. Windows were cut in it to allow airflow. Louvers were installed to keep the rain out. However the sheet metal guys did a HUGE overkill on designing the louvers. I want to propose to my boss to remove half of the louvers so that we can get decent air flow...

Homework Statement A large tank of water has a 'z-shaped' hose connected to it. The tank is sealed at the top and has compressed air between the water surface and the top. When the water height, h, has the value 3.50m, the absolute pressure p of the compressed air is 4.20x10^5 Pa. Assume that...

Homework Statement As shown in the figure, if the pipe net work is shifted bodily by 10m vertically up the tank, and all the other conditions remain the same as the previous figure. Will the volume flow rate change? Or I rephrase it as, in the calculation of elevation head of pipe flow, is the...

We have a situation. Someone modified the exhaust pipe from a diesel fired equipment. Exhaust gas flows out through a 30mm internal dia pipe. The modification carried out was to reduce the diameter of the pipe to 20 mm internal dia. The Exhaust outlet temperature from the equipment was 400 deg...

Good morning, I always walk on egg shells posting what is probably a redundant question on a forum. I have been reading for two days and there is a ton of physics information out there on the subject but most of it doesn't truly address the mechanics of what I am looking for. In a very...

Hello, I would like to know, what happen with accretion (cloud) when drop toward a black hole. In Bondi case and terminology. If I understand: 1) We describe the cloud falling to star (black hole) by EoS P(\rho)=K\rho^\Gamma . 2) This accretion is steady it means \dot{M}=4\pi r^2u\rho=const...

I am a physics student with very limited experience in electronics and I have been tasked with making an receive coil for use in an MRI machine. The design of an RF coil amounts to constructing to what essentially amounts to an LC resonator with a set resonance frequency. The design of my coil...

Homework Statement when the balance point is achieved , there're no current passing thru , so Galvanometer should show 0 . Am i right... so there's no current passing thru the 20 ohm resistor . so my working is ( 8.1/120 )(40) = 2.7 V ... correct me if I'm wrong...Homework EquationsThe Attempt...