Pressure drop Definition and 147 Threads

I have a tank which has a Pressure Relief Valve (PRV) connected to the atmospheric vent (Carbon steel with friction coefficient of 0.14). The PRV is opened at Set pressure of 30 PSIG and has a capacity of 60,000 SATSTM (I assumed it to be in lb/hr). I am trying to calculate the discharge...

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

What is the reason that the pressure drops in the central circulation?especially if you go from arteries to arterioles you get a huge pressure drop. If you look what is changing if you go from arteries to arterioles then it is that you get many many branches this leads to an increase of total...

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 read something about the pressure drop across a valve and it was specified this is a singular pressure drop equivalent to K*U²/g (Borda formula). My question is, can we used the Bernouilli formula for a permanant incompressible flow to determine the flow rate function of the pressure...

When designing the fuel plumbing for an efi system, do pressure drops in the fuel lines need to be considered when there is a pressure regulator? If so why? Been reading up a lot on plumbing design lately about how the goal is to minimize restrictions in the lines which ultimately cause...

A building has a water pipe inlet. I have found that at if I open the valve at this location fully, then I get 180 liters per minute at a residual pressure of 0,2 bars (static pressure is 5,4 bars). Is there a fixed relationship between the flow and pressure drop so that I can easily predict...

Hey Guys! Anyone able to help out here? I have already happily solved for T2 = 369.91K and m2 = 11.492kg However, for question 2.3, I'm terribly stuck. I'm not even sure what to make my control surface. How can I relate pressure outside the valve with the two thermodynamic states I have...

Hi guys, I don't know if you can help me, or if I am asking my question correctly but your feedback will be greatly appreciated. I have a 2" piping system that connects a scrubber that is rated for 675 psi (36" OD x 7'-4") to another scrubber rated for 75 psi (84"ID X 24'- 0") ; there is a...

Homework Statement Helium is stored in a tank initially at temperature To and pressure Po. It starts coming out through an opening (pipe outlet) at a constant mass flow rate of mdot. Calculate the decrease in temperature and pressure of the tank (assuming no heat loss to the surroundings) as a...

Hi all, I am designing an artificial rain system and was thinking about using http://www.dannermfg.com/Store/Products/Danner/PID-02720.aspx to power it. The goal of the system is to deliver roughly 1 gallon of water per hour to each of the 8 exit points (I will measure this by using a bucket...

I would like to clear out my understanding of gas compressor. If it is moving at constant RPM, is it mean that it can only allow same volumetric flow rate all the time? So the power will remain constant too, (P=VI) then voltage and current will varies. My investigation is to find why there is...

Hello all! I am interested in how much energy a HVAC VAV box consumes. Can anyone help me come up with the following equation? I don't need to know the exact formula, and can assume an uncompressible fluid and/or ideal gas. Been about 20 years since I have done this and am a bit rusty...

Hi, what happens when I have a single pipe with pressure 1bar. I split this pipe into 3 equal pipes with equal diameter. What will be my pressure at the ends of these 3 equal pipes ? From what I have been reading on the internet it seems that the pressure will be the same on the 3 equal...

I have a container with one inlet and one outlet. I have the area of the inlet, Ai, velocity vi of the air coming in, and mass flow mi (assume a plane with an air inlet to a bay). I don't know anything about the outlet (just that there is one). What I need to do is calculate the size of an extra...

Of the few occasions I've seen Airfoil Lift described to general audience (on documentaries), it has focused on the top-side curve of the Airfoil causing air on the topside to move faster than the bottom-side. This is said to reduce air pressure on the topside and result in lift. If a wave is...

Hey everyone. Four days ago I didn't know anything about fluids but I started my internship and got assigned a project that is all about fluids! And I need some help, this topic can get really complicated but I'm trying to take it one step at a time. Problem Description: There is a pump...

THIS PROBLEM WAS MOVED FROM GENERAL PHYSICS TO THIS FORUM BECAUSE OF ITS HOMEWORK-LIKE NATURE. SO THERE IS NO TEMPLATE. Pressure vessel has a electrical (coiled) furnace inside. A pressure vessel @ 550 bar @ 500 C containing argon has its gas inlet pipe (1 inch ext Diameter) that has come...

Hi, I hope this is the right section. I'm trying to figure out a rough estimate of the pressure drop in a spiral heat exchanger. The fluids both being water. My guess it it would be in terms of the surface area of the inside of the heat exchanger, and the flow rate, but I can't seem to nail...

MODERATOR NOTE: THERE IS NO TEMPLATE BECAUSE THIS THREAD WAS ORIGINALLY MISPLACED IN A NON-HOMEWORK FORUM Viscous liquid (ρ = 1460 kg/m3, μ = 5.2×10−1Ns/m2) is pumped through a smooth pipe with a 0.1 m diameter, at a rate of 5×10−2m3/s. Using your Fanning friction factor versus Reynolds Number...

Hello, I am currently a chemical engineering major and i have a question. What exactly does pressure drop tell you? i know the equations to solve for pressure drop for various situations (using ergon equation for a bed, or skin friction for pipes, using friction factor, etc etc ( is there...

Hi I am new to fluid mechanics and I wondering if anyone can explain to me in very simple terms why friction causes pressure loss when steam is moving through a pipe? I thought the friction would slow down the fluid which will lead to higher pressure but it seems its the opposite. I was trying...

Homework Statement The accompanying figure shows a horizontal ring main consisting of a single loop of pipe, as might be used for supplying water to various points on one floor of a building. Water enters the main at A at 50 psig and is discharged at B and C at rates of 20 gpm and 60 gpm...

Anybody can help me for calculating pressure drop in pipeline. I really appreciate the suggestions from your side. i have the values of dp for equipments and valves...i want to know how to interlink with these dp values for calculation...i want to know, how to calculate the dp of scrubber. i had...

I am trying to size an orifice to place on an outlet of an air vent line. The reason for this is that I am installing a noise suppressing muffler, but it is only rated for 300 psig. Since I am venting a line that will be pressurized to 1600 psig, I'd like an orifice restrictor in order to...

Hi, I just started a course in drilling and the first chapter is about various situations where pressure drops in the drill string (pipe) causes forces on the pipe. I understand that a pressure drop due to friction causes a downward force on the pipe. The fluid is "pulling" the pipe down...

Take a cylinder in cross flow. We know that for Reynolds number greater than 40, we will start to see vortex shedding occur. Using the Strouhal number, we can determine the frequency at which vortices will shed. Using the coefficients of drag and lift, we can determine the steady loadings on...

Hello everybody. I have seen many people asking questions on this forum about the reason to why blood pressure drops as you get farther from the heart. But honestly, not a single answer satisfied me. My major is physiology, so it's quite funny that I still don't know this "trivial" detail. What...

Hello there, I am having a discussion with a co-worker about a pressure drop test. I have two different 'boxes' for which I don't know the pressure drop. What I want to know is the difference in pressure drop between the two 'boxes'. Knowns 1) PA1 = PA2 = PA = Inlet Pressure for...

Hello. I have had an attempt at solving this pressure drop problem, but I have been told it is incorrect. I am very much a beginner in the area of fluid mechanics, so if you could please define any terms that you are using, that would be so helpful! I thought using the Hagen-Poiseuille would...

Homework Statement ΔP = 1000 x 9.81 x (Orifice pressure drop in m) Pressure drop across orifice = 470.72 Pa 2. Homework Equations 3. The Attempt at a Solution I am not sure how this works. How can pressure be converted to meters? It does not make sense to me. Any...

Homework Statement ΔP = 1000 x 9.81 x (Orifice pressure drop in m) Pressure drop across orifice = 470.72 PaHomework Equations The Attempt at a Solution I am not sure how this works. How can pressure be converted to meters? It does not make sense to me. Any help would be much appreciated...

Homework Statement Air at 100 F is flowing through a packed bed of spheres having a diameter of 0.5 inches. The void fraction (ε) of the bed is 0.38 and the bed diameter is 2 feet. The bed height is 8 feet. If the air enters at 16.2 psia at a rate of 47.5 lb / min calculate the pressure drop of...

Hello guys, I am a computer science PhD student. But my project somehow requires some knowledge about computational fluid dynamic modelling (both discrete and continuous). nowadays I am abit stucked in an issue. I want to model pressure drop across a filter medium dynamically. i assume i have...

Homework Statement Hi everyone, I'm trying to calculate the flow rate of air in straight tubing that is 30cm long and has a diameter of .1875 in and has an outlet into a 100 mL vial which is vented to the atmosphere. The starting of the system pressure is 20 psi and the ending psi is 14.6...

Homework Statement The Black Mesa pipeline transports 660 tons / hr of solid coal ground to 8 mesh (2.4 mm) as a 50 wt % slurry in water with an estimated sg of 1.26 for 273 miles across northern Arizona. The pipeline ID is 18 inches and the slurry flow rate (coal and water) is 4200 gal/min...

Homework Statement Water flows at room temperature in a horizontal pipe with mean velocity of 1 m/s. Then a sudden contraction of the pipe changes the diameter to half the upstreams diameter (##\frac{D_1}{D_2} = 2##). What is the pressure drop (##p_1 - p_2##) from a point (1) upstream of...

Good afternoon, I am trying to size a reduction orifice for a desired pressure drop. I do not need the drop to be specific, since this is just for valve protection and not for metering. D1 (Pipe) = 2.5" P1 = 125 PSI P2 Required = 75-85 PSI Q = 1020 gal/hr Fluid = Water, 90 Deg F...

hi friends, I am confused with incompressible and compressible flow.Can i use moody diagram for air compressor.How can i calculate pressure drop in pipe.

I am having a problem with an air pressure drop. I have a supply of 100psi of around 4scfm. I have it regulated down to 90psi, but when I turn on an air turbine motor my regulated pressure drops momentarily (1-2sec) down to 80psi. This drop in pressure is unacceptable to other components in my...

hello all... Please can i know physically why the pressure drop in a fluid when there's shear stress? what happens? thank you

I wanted to know the function of a pressure regulator.. Am using one to control liquid flow rate. Here is my understanding- A pressure regulator can be connected across a valve. The pressure regulator maintains a constant "pressure drop" across the valve so if i set it to give a drop...

Hello... I can't find the difference between the pressure drop in a pipe due to frictionnal loss and the Pressure difference that cause the flow like in Poiseuille Flow.. Thanks

Hello, I'm struggling with the following problem. We have a dryer in our plant which evaporates acetone and with a blower the vapour is driven to a scrubber. However the efficiency of the scrubber is not sufficient and that is why I want to place a plate heat exchanger in the vapour line to...

Hi folks, my prof gave us some problems calculating pressure drop in two phase flow. She did some examples and somehow she got the density of water-liquid and water-vapor from steam tables, but she did not explain how. I have never used these. I am especially stumped on the density of...

Hey all, I'd need help with determining the pressure loss over an orifice in a pipe. I have an equation for the friction factor so no problem there, and I know the Reynold's number as well. What confuses me is choosing the suitable velocity for the pressure drop equation; \frac{Δp}{ΔL} =...

Let initial preasure (P) = 10 bar,volume of container (V)=100000 cubic cm. At what time period pressure will become 5 bar.

Along a horizontal pipe I am getting a pressure drop of roughly 10-20 kPa every 20 metres in a 6.5" (OD) water pipe. This seems much to high and I am thinking the pipe may be stuffed and thus there is to much friction which is reducing the pressure of the water. Just wanted to get some other...

Blood is in continuous contact with itself. Thus any pressure on artery blood is pressure on vein blood. So they have the same pressure. What am I missing here?

Hello, I have abnormal situation on a site, there are installed 3 valves in parallel (cascade) in Fuel gas skid, upstream pressure of the valve is 30 bar, downstream pressure 25-26 bar, when 2 GTG starts up to load 40 MWt (100 %) the downstream pressure of the control valves decreses to 21 bar...