Flow Definition and 1000 Threads

How do I determine the pressure drop of air across an opening? For example if I have 3,000 L/s (3 m3/s) and an opening of 8.4 m2 I know the velocity is 0.4 m/s. If the free area is 80%, the velocity increases to 0.45 m/s. What I'd like to cal is the pressure drop in each case. Cheers

(a) FIGURE 2 shows two cylindrical tanks interconnected with a pipe which has a valve that creates a constant resistance to flow of Rf when fully open. The height of liquid (of density ρ) in the first tank is hin and the second tank hout. The cross-sectional area of the first tank is Ain m^2 and...

Homework Statement [/B] For many liquids the viscosity is strongly dependent on temperature. Use the table below to estimate the required maximum temperature of crude oil to flow at a rate of 4Kg s-1 through a 0.3 metre diameter pipe whilst maintaining a laminar flow. In the table it has in...

Hello, I am new in this field, so maybe my questions will be stupid :) sorry for that :) In the company where I work, they measure flow rates of wastewater using Flow meter (Doppler device). The problem is, that the flow rate is very low, so this device is not submerged completely in the...

Homework Statement for part c , why when the vane is moving , the flow rate doesn't change ? ? Homework EquationsThe Attempt at a Solution The flow rate is given by the formula Q=Av , where A = area , v = velocity . IMO , when the velocity of vane change , the flow rate is no longer 0.687kg/s...

Hi, I am mike from australia, I am new to the forums and am having trouble answering the question below, I have included some information on the experiment as well. You are given a water bottle with a pin sized hole in the bottom, and a line drawn around the bottle at the level that 50cm3 of...

Homework Statement what does the author mean by if P is below the surface of B then h2 and Q2 are both 0 ? Homework EquationsThe Attempt at a Solution at the last second line from the bottom , the author gave if P is below the surface of B then water must be out of B and Q1 +Q2 = Q3 ? both...

Hi everyone I searched about the mass flow rates and temperatures of exhaust gases of light gasoline internal combustion engine at different condition but I don't fond anything yet . Anyone can guide me? .

Hi, all I am working on a project that involves analyzing fluid flow behavior in oil & gas pipelines. I am interested in calculating and plotting the velocity profile, and also(pressure distribution, temp distribution) Having studies fluid mechanics last year I am aware of the EOS for fluid...

Homework Statement I'm going to regulate a tank using a PID-controller. I want to simulate this in MATLAB though and met a problem while calculating the mathematical model. The problem is the following: The three valves are either fully open or fully closed. The diameter in the pipes are all...

Homework Statement As we all know , energy will lose from high to low. in the equation , the energy at A ( Pa +za +](Va)^2 ]/2g ) is higher , while the energy at B is lower. So, why the water flow from B to A ? why not A to B ? 20.39 +10.52-hf = 32.98 Homework EquationsThe Attempt at a Solution

I can't articulately ask the question so I drew a diagram. In the diagram, both capacitors are equal in capacitance. The bottom inductors are both 10000 nh and the top are 100 nh. A. Will the capacitors charge at the same time? B If we switch the large inductors to the top and the small to the...

Is the Blasius solution valid for internal flow in an underdeveloped pipe? Can the function for the boundary layer thickness be used to calculate when the boundary layers will meet in the center of the pipe? I don't see how it could be valid since the assumption in its derivation is that...

If we have 2 Tanks connected with a siphon but the water in bigger tank is higher than the water in smaller tank, but the siphon goes from smaller tank over to the big tank and ends up at lower elevation than it started. Will the water flow in big tank like in the picture.

Hi, I'm seeking the formula to calculate how water moves from one tank into another through a perforated plate driven by waterlevel compensation. I found the calculation for the discharge of water through submerged orifices, but I think the calculation does not include that holes, one above the...

Homework Statement A 15 cm. radius cylindrical air duct is used to replenish the air of a room 10 m.*6 m.* 3m. Every 10 minutes. Determine the speed of the air through the duct in m/s. A1=15 V1=? A2=19 V2=0 Homework Equations A1V1=A2V2 The Attempt at a Solution 3.14*15^2 * ?= 19*0=...

Hi. I'm a computer science student developing a kalman filter for autonomous sailboat, but I severely lack knowledge of the physics behind sailboats. I have a wind sensor giving data about wind speed and wind velocity, problem is the data is unreliable. So i thought that i could estimate what...

Homework Statement In the figure, the top wire is 1.5 mm diameter copper wire and is suspended in air due to the two magnetic forces from the bottom two wires. The current flow through the two bottom wires is 70 A in each. Calculate the required current flow in the suspended wire. Homework...

This is not homework, but something work-related. However, I will post it here since it's homework-relatable. 1. Homework Statement Known variables: Qin , A (and obviously the diameter D of the pipe as well as g = 9.81 m/s2). The pipe outlet and the top of the tank is at atmospheric...

why is it useful to compare viscous flow to inviscid

Homework Statement . Air, at a flow rate of 30 [N/s], flows through the reducer shown below. In the 300 [mm] diameter section of the pipe the specific weight of the air is 9.8 [N/m3 ]. When flowing through the reducer the pressure and temperature will fall causing the air to expand and...

This is it; most likely the last time I bother the people of this website with my questions on traffic flow. I'm trying to figure out some concrete examples to demonstrate utilization of the conservation equation in traffic flow: \frac{\partial \rho }{\partial t} + \frac{\partial q(\rho...

Homework Statement I have this problem in an online assignment. Someone told me the answer, so I already got it right, but I don't know why my logic leads me to the wrong answer. The problem: The temperature u of a star of conductivity 1 is defined by u = \frac{1}{sqrt(x^2+y^2+z^2)}. If the...

So I'm trying to create a very simple mathematical model for a very idealized theoretical situation of traffic flow. In this situation I'm considering vehicles to be points (no length) each going the same speed with the same distance between them. The vehicle in front (vehicle 1) slows down and...

Homework Statement as we all know , D=4R , D=hydraulic diameter , in the equation of P= (8μLV_avg) / (R^2) , i would get (128μLV_avg)/ (D^2) , am i right ? why the author gave (32μLV_avg)/ (D^2) ? Homework EquationsThe Attempt at a Solution

Hello, I'm doing some online research on fluid flow in waste water treatment. One of the problem I'm trying to find information about is how can visible particulate matter be separated within a liquid. I saw the following picture: What fluid concepts are going here that allow the grit to...

I am trying to come up with a mathematical model so that, when the displacement of the plunger of a syringe is know, I can calculate the amount of a specific liquid in the barrel. Or the relationship between the speed of the plunger and flow rate at the tip of the needle (Again assuming that the...

Okay guys I am a beginner (in electrostatics as i just started studying it) I am thorough with kirchhoffs rules/laws But one thing which bugs me is this doubt So in the book that i am reading It says that even if the potential difference is zero,current flows through a wire I don't get how I...

Hey guys, long time reader first time poster. I'm undertaking a project in partial fulfillment of my Mechanical Engineering degree with regards to the cooling of an intercooler heat exchanger with an exterior water spray. basically i have an intercooler and i am using a hair dryer to supply a...

Hi, First-timer here! I'm designing a physics project that involves pumping a certain pressure of air into an empty bottle. SETUP: The bottom of the bottle has a small hole through which a thumb tack fits tightly; the top (cap-side) has a valve through which the air is inserted. The bottle is...

Homework Statement A cylindrical conductor with a circular cross section has a radius a and a resistivity ρ and carries a constant current I. What is the flow of energy into the volume occupied by a length l of the conductor? Discuss why the energy dissipated in a current carrying conductor, due...

Hi guys, I was wondering if you could help me with something. I work in the paper industry with what is called a suction roll. The roll has a rotating perforated steel cylinder with a stationary vacuum box on the inside and as the wet paper web travels over the surface of the roll, the vacuum...

"For a particular flow rate, the pressure drop due to the downward flow of the fluid is balanced by the pressure gain due to gravity—that is, at this flow rate, the static pressure in the pipe is independent of the distance along the pipe." Book says this. Can you explain how the pressure...

1. Air at 0∘C flows through the tube shown in the figure. Assume that air is an ideal fluid. What is the air speed v1 at point 1?2. Formulas: A1V1=A2V2, ΔP + 1/2ρΔV2, ρgΔh3. My first through process was to calculate the change in pressure in the mercury as the change in pressure in the...

Homework Statement what is G and γ mean here ? Homework EquationsThe Attempt at a Solution

Im reading this stack exchange question: http://electronics.stackexchange.com/questions/28897/how-to-choose-value-of-resistor-in-voltage-divider So there is a 5V circuit with 2-100 Ohm resistors that yields a voltage drop across the divide of 2.5V. The current through the circuit is 25mA...

Homework Statement An turbine expands air at 1300 kPa and 500oC to 100 kPa and 127oC. Air enters the turbine through a 0.2-m2 opening with an average velocity of 50 m/s, and exhausts through a 1-m2 opening. Determine (a) the mass flow rate of air through the turbine Homework Equations PV=RT m...

I have some questions concerning hydraulic engineering. I'm currently working an simulating laminar flow. This laminar flow is induced by a pressure gradient. The assumed length is 1 meter, therefore the pressure gradient is equal to the actual pressure in reference with zero. What are typical...

is it correct modeling mathematical model for Compressed air engine, As here air Flowing through Pipe in Kg/s and its not a continuous flow and flow through vent into the cylinder and pushes Piston and and Piston moves down. As I created model like this (P1*V1)^Y = (P2*V2)^Y So, P2 =...

I understand that there are vortices formed on the delta wing for moderate angles and low speeds. I observed recently 2 asymmetric vortices forming on a small delta wing model for a moderate angle and a low speed. But, why would there be asymmetriic flow over a delta wing? If the flow is...

Hi all, How would one go about determining the flow(GPM) of a closed loop parallel piping system. I believe this has to do with the pressure intake and outlet of the pump as I have a pump in the mentioned system rated at 4350GPM@50Hz but it is pumping at 4500 GPM at 37Hz, Thank you all for...

if a gas expands isentropically (consider the process reversible adiabatic), from point 1 in a nozzle to point 2 downstream of the nozzle. If you know the pressure and temperature at point 1, can you use the relationship pv=1/M RT to work out the specific volume at point 1? And similarly if you...

The Earth is a geodynamo. It is an electromagnet because a net current flows in the molten iron in the mantle. My question is, which way does the current flow? The northern magnetic pole is a South pole, so the magnetic field points north at the equator.

I want to ask why flow has high velocity when partially closed. Eg. when we partially close garden's hose pipe, the flow goes much more farther than when fully open. Supposing water is flowing through a pipe from a constant level water tank. Why flow has high velocity when partially closed...

Hi All, I have a situation were I need to evaluate the heat transfer coefficient of a horizontal surface. The surface has tubes within although I first used "flow across a bank of tubes", this has been untrue due to the air flow coming from above the surface flowing vertically (and...

Hello All, I am trying to figure out the solution to a problem I am trying to do for fun. I've been trying this for a while and has annoyed me so any help is greatly appreciated! I attached a picture of the problem/ control area to help...

Picture a Ø160mm duct 10m in length, open at each end. Then I install an in-line fan at one end so that it blows into the duct and just let it run at full power. How can I determine what the air flow will be? I startet thinking about it and was just surprised that I didn't know how to approach...

Hello, I'm trying to learn about the role that differential equations play in traffic flow, and how I can use them to model/predict/whatever you do with them with traffic flow. Do you guys know of any good and in-depth (preferably online and free) resources I can use to learn about this?

I thought I was following and understanding a lot of ideas about Black Holes until I revisited the concept of Spacetime 'flowing' within the Event Horizon and, assuming a singularity, disappearing. Now, The Hawking Radiation can be encoded with the information patterns for MATTER (which is...

I was reading a bit about comrpessible flow and I came upon a problem, there's a diffuser which has air at Ma=0.9 at its inlet and the air comes out at 0.65, how should I go about finding the ratio of the inlet and outlet areas? I know It's related to this equation but I'm unsure about how...