Pressure Definition and 999 Threads

Hello all, I'm trying to calculate the pressures exerted back on a piston by a working hydraulic fluid in a damper system. I've attached a drawing of the system and the equations I'm using. Essentially the piston motion is restricted by flow through an orifice. I have data for the flow rates...

Net Inlet Pressure Required (NIPR) is an individual pump characteristic, determined by test, of what pressure energy is needed to fill the pump inlet. How to generate the curve of NIPR or how to know NIPR of the pump if I am a pump manufacturer??

Homework Statement An automobile tire is pumped up to a gauge pressure of ##2.0 \times 10^5 ## Pa when the temperature is 27◦ C. What is its gauge pressure after the car has been running on a hot day so that the tire temperature is 77◦ C? Assume that the volume remains fixed and take...

Hello everyone, I am pondering on the airflow around a wing: When air flows over a wing, part of the air goes below the wing and part over the wing. Even when the air is moving, the pressure at a point in space is always isotropic. The pressure on top of the wing is slightly lower than than...

Good day everyone. I have a few question that I would like to confirm. Currently I am doing a project that rinses a plastic pallet. The type of nozzle I am looking at is a 65 degree full cone nozzle. Pressure = 0.7 MPa. Flowrate = 3.88 lpm. Pallet size is 1300mm x 1300mm x 100mm. Q1. Is it...

We are trying to design a new product which uses gas pressures in various ways. We are a little foxed about partial pressures: Imagine a small cylinder; 6in long + 1in in diameter. The cylinder is made from steel. The cylinder is divided into two equal compartments – A and B. Each compartment...

Homework Statement [/B] A 25-cm-diameter, 100-cm-high cylindrical container, (as shown), is partially filled with 75-cm-high liquid (density = 900 kg/m3). Determine the rotational speed at which the liquid will start spilling. Calculate the gauge pressure at the centre of the bottom of the tank...

Homework Statement An organ pipe with one end open and the other closed is operating at one of its resonant frequencies. The open and closed ends are respectively: A. pressure node, pressure node B. pressure node, displacement node C. displacement antinode, pressure node D. displacement node...

Greetings, I am trying to understand how to setup/solve for the pressure drop across an orifice L=3.5in The pipe diameter starts at 1in, then abruptly decreases to 0.5in for the length of the orifice, and abruptly transitions to 1in diameter. (See the attached file for an illustration.)...

Hi. If I fill a glass with water up to the top and close it with a coaster, I can turn it upside down without the coaster falling off and spilling everything. Usually, this is explained with the atmospheric air pressure being bigger than the pressure of the water inside the glass (hence, it...

So the pressure for a canonical ensemble is: P = kbT dZ/dV P = pressure P = -∑pi dEi/dV Z = ∑e-βEi pi is the probability of being in microstate i Ei is the energy of state i β = 1/kbT <E> = U = average energy U = -1/Z dZ/dβ = -d(Ln(Z))/dβ How can the pressure (given above) be derived in...

I still struggle with the interchangeability of pressure and temperature and how they affect the performance of various bits of turbomachinery. Microscopically they're very interconnected, in that the measure of pressure is the result of the confinement of the measure of temperature, however...

Homework Statement A closed hemispherical shell of radius R is filled with fluid at uniform pressure p. The net force of the fluid on the curved portion of the shell is given by:Homework Equations The Attempt at a Solution [/B] I'm not even posting the answers because I'm not looking to get...

Basically what I'm trying to do is calculate the amount of water it would take to generate a given pressure at the water tap. Or to put it more simply I'm trying to figure out where the water line is damaged, well more for fun then actually being practical. The water system is simply a well on...

Hi, I have a vessel/chamber filled partially (25%) with silicon fluid (coefficient of thermal expansion is 0.00096 cm^3/cm^3/ °C) and the rest is filled with nitrogen gas at a certain pressure (P1) and temperature (T1). my question is, how to predict the final pressure (P2) If I increased the...

Homework Statement A uniform star has a mass of M and radius of R,use the hydrostatic equilibrium equation to find its centre pressure. (note: not the minimum centre pressure) Homework Equations $$\frac{dp}{dr}=-\frac{Gm\left(r\right)\rho \left(r\right)}{r^2}[1]$$ The Attempt at a Solution...

Greetings, I have very little experience with fluid dynamics and I was wondering how I can calculate a pressure drop across an abrupt change in diameter of the piping used for water. Any help is appreciated! Thanks!

A smooth flexible tube 1mm in diameter and 1 foot in length holds air at normal / atmospheric pressure (14.7psi). the tube is open at one end. the other end is connected to a tank by an open valve. the tube is peristaltically compressed so all the air in the tube is forced into the tank. the...

I feel like this is easy to answer but I'm coming up with answers I don't trust. Basically, I have a tank of air where I want to keep the pressure at a certain value. Let's say 1 psig for the sake of argument. I have a 1/2" ID hose connecting to inlet flow to the tank and an outlet hose of 3/4"...

Hello, I came across this line in my textbook: "Total peripheral resistance (TPR) increases diastolic pressure more than systolic pressure." I don't understand how the peripheral resistance would increase the diastolic pressure more than the systolic pressure? Could some one explain that...

Homework Statement I have two closed bottles one has a smaller volume that the other. (initially atmospheric pressure in both and then closed with a cap) If I heat both bottles up, which one will increase in pressure more the larger bottle or smaller one. Homework Equations PV=nRT ? The...

I'm studing classical physics and I'm stuck with the simple pressure formula defined as: P=\frac{dF_{\perp }}{dS} Now, i know some calculus and the concept of infinitesimal in physics; however what i don't understand is : 1) according with the fact that in Calculus dF_{\perp } represent an...

High blood pressure can affect health in many ways. No one treatment can control it in all cases. Treating immune cells may help control it. Science mag news article here.

Greetings I am asking about the reliability of using a thermal gun to check if there is passing downstream the valve. The fluid is either steam or air. Wouldn’t the pressure and temperature drop sharply downstream the valve if it is closed but passing ? again I am talking about air or steam...

Hi There, Why is a pipe with a smaller diameter able to withstand a greater internal pressure than a pipe made from the exact same material and wall thickness but larger diameter? Thank you

Hi, Let's consider a cylinder of infinite length and fluid flowing "over" (I'm not sure of which words I should use, sorry) it like in the figure: Let's consider x>>D in order to neglect what's happening near the rear surface of the cylinder. Let's get rid of static pressure which doesn't...

Hi There, I have constantly come across the fact that as fluid (hydraulic oil say) travels along a pipe you will see a continual drop in pressure the further you travel down the pipe. Am I right in saying that the pressure at any point is simply the result of the resistances (friction with pipe...

Question #1 - A lobster tank in a restaurant is 1 m long by 0.75 m wide by 60 cm deep. Taking the density of water to be 1000 kg/m$^3$, find the water forces (a) on each of the larger sides of the tank; (b) on each of the smaller sides of the tank.

Homework Statement [/B] Homework Equations - The pressure drop equation. [/B]The Attempt at a Solution

So my question is - would a strong enough negative pressure be able to pull a gas through a liquid? I can draw a diagram if anyone needs it but I'm trying to figure out what would happen in the following situation. Imagine you had a solid pipe that formed a large U shape with one end sealed...

Hello, The Darcy losses are pressure losses in the dynamic, static or total pressure? Also, the pressure losses in various fittings (eg. bends) are they dynamic, static or total pressure? Also, how can we calculate the static pressure? Is it the hydrostatic pressure of the amount of water...

Homework Statement I am after PC - PA However I must do so without breaking into components. My problem has different values L=3 H=4 SG=1.2 downward a = 1.5g horizontal a = 0.9g and my coordinate is conventional positive y up and positive x to the right cos##\theta## = 3/5 sin##\theta## =...

I'm reading a book on thermal physics and the author says this: "In general, the internal energy will be a function of temperature and volume, so that we can write U =U(T,V) " How do we know this intuitively and how do we know that internal energy is not a function of pressure as well?

Homework Statement I drew a picture[/B] Homework Equations I drew a picture The Attempt at a Solution I drew a picture

I need help understanding P=pgh and Bernoulli's equation.

Homework Statement Hi, I trying to calculate principle stresses for pressure vessel (thick walled) which is pressurized from inside. I calculated all 3 stresses radial, hoop and axial and looking for what formulae to use to get to principle stresses. thanks Homework EquationsThe Attempt at a...

Homework Statement a) A mass of 0.12 kg of air has an initial temperature of 500°C and pressure 0.8 MPa. If the air is expanded according to the law pV1.2 = c to a final volume of 90 litres, determine i) its initial volume, ii) its final pressure, iii) its final temperature...

Hi, I'm doing a pressure test with a liquid medium. I have a fixed volume and I know the pressure drop, and temperature change - how do I calculate volume of liquid lost in a leak?

Homework Statement Prove that the hydrostatic pressure difference between the liquid surface and the base of rightmost tube is ρgh (h is the vertical distance of the liquid surface from the base ) ? Homework EquationsThe Attempt at a Solution I would like to prove this result just out of...

I'm aware that the term means the remaining pressure at a point while there is flow. Say the distribution pipes downstream the sprinkler valve have a calculated total head loss of 3 bars during the designed flow. Does that mean that the residual pressure at the sprinkler valve needs to be at...

Homework Statement Here is a pesticide spray vessel, of total volume of 10 litres, containing 8 litres of pesticide. Valve B is closed first,and the space above the air is filled with air at a pressure of 200KPa until the desired pressure is reached, and then valve A is then closed. The...

Say I have a simple 2 or 3mm thick sheet of plexiglass or aluminum, and I have a closed chamber box out of these sheets. Now, I want to build a pressure inside the chamber, but the prototype only has a simple O shaped "hole" on the box. I can choose the diameter of the hole, and I have a rubber...

Hello everyone, I am currently working on an undergraduate club team for the Intercollegiate Rocket Engineering Competition. I am attempting to do a calculation to determine the pressure needed in a vessel leading to another pressurized combustion chamber to achieve a desired mass flow rate...

Homework Statement [/B] Hello, am i on the right track with this problem. I am not sure if i have done the it correct. The part i am unsure on is b). Not sure if i have calculated it correct. Part of a sea defence consists of a section of a concrete wall 4 metres high, and 6 metres wide. (See...

Hi, I'm looking into how phonon dispersion changes with pressure analytically and need to know how the atomic spacing in copper changes with pressure in order to model the crystal. I can't find any helpful papers online :( Any help would be appreciated thanks e

A balloon is filled with a gas to a certain volume at a certain pressure at 22.0 degrees Celsius. If the pressure exerted on the balloon is doubled. explain what must the temperature ( in degrees Celcius) be so that the volume of the balloon doesn't change. If the temperature changes, the...

Hello, Im designing a product which will pump components as vacuum cleaner does. I have 2 questions: Im trying to calculate the pressure different in order to pump those metal component with : M=0.2 kg , dimensions (mm) cylinder with diameter 5.5 mm length 600mm . the formula for pressure...

I came across this pie-in-the-sea concept: (Obviously, the pictured structure would be extremely susceptible to complete catastrophic failure, having no apparent internal means of water-tight seals to prevent complete implosion. Which is why you'd more logically build a city in tube-and pod...

Homework Statement a uniform fine chain of length l is suspended with lower end just touching a horizontal table. Find the pressure on the table, when a length x has reached the table.. Homework Equations Pressure = force/area The Attempt at a Solution let mass density, m= mass/l...

I'm studying fluid dynamics and we just had a lecture about the momentum equation. We started the lecture by talking about pressure in terms of molecules moving across a hypothetical surface element and carrying their momentum with them (in both directions). There are 2 things confusing me about...