Compression Definition and 633 Threads

  1. G

    How to calculate stress on a pipe wall

    I have a PVC fitting that keeps cracking. The fitting consists of 2 parts. One piece is placed over the end of a flexible PVC ribbed hose, and the other is inserted inside the hose. The 2 parts act as a compression fitting to attach to the end of the hose. The hose typically has an outside...
  2. DaynaClarke

    Gas Compression Temperature Change

    Homework Statement "One way to heat a gas is to compress it. A gas at 1.00 atm at 25.0°C is compressed to one tenth of its original volume, and it reaches 40.0 atm pressure. What is its new temperature?" So, I have: P1 = 1 V1 = 1 T1 = 25 P2 = 40 V2 = 0.1 And I'm looking for T2 The question was...
  3. S

    Leverage and Forces on a Pivot System

    The diagram drawn below shows a lever system fixed to a point on the left with a pivot point (circle) on the line which attaches to vertical line. I have dimensions for Y and Z and the forces pulling the lever down on the right, and the force acting upwards from below. I am trying to work out...
  4. P

    Water spray to steam during compression in a hybrid diesel-steam engine

    I just have read about a new kind hybrid diesel-steam engine where water has been injected inside an internal combustion engine to improve efficiency. The basic principle behind the process is that water will soak up a large section of heat generated by burning the fuel and will turn into steam...
  5. D

    Normal Stress: Compression vs Tension

    Homework Statement Homework Equations Equation of Equilibrium (Horizontal and Vertical Forces, Moments) Normal Stress = F/A The Attempt at a Solution I have already solved the solution for this problem. For part (a), I simply found the force in the link, and used the cross area where the...
  6. BrainMan

    How can I calculate the work done in a gas compression problem?

    Homework Statement Homework Equations ΔEth = nCvΔT W = -∫ p dV pV = nRT The Attempt at a Solution I tried to find the total change in thermal energy by finding the temperature change. I first found the initial pressure P1 = nRT/V = 32464.4 Pa Then I solved for the final pressure...
  7. H

    What Happens Thermally When High-Pressure Air Bursts into a Dead-Ended Tube?

    I have a question in regards to a specific situation and really don't know which elements are significant. The example is high pressure AIR (a real gas/ not ideal ;-) of relatively unlimited volume, released via a rupture diaphragm into an enclosed tubulation. (dead ended) Relative dimensions...
  8. SpinzTronics

    Thermodynamics - expansion, compression, work

    Hi everyone! I am confusing myself with this topic and I would appreciate some insight into this. You see, one takes the area of a PV graph to obtain the work done on the system (for compression) or by the system (for expansion). However, I am learning that in the irreversible path, compression...
  9. grandpa2390

    Why is the equation for compression work P=kV and not P=Pi/Vi?

    Homework Statement I am doing a problem of compression work. in order to solve it, I have to find an equation for the line and integrate it to get the work. But I don't understand why ##k = \frac{P_i}{V_i}## Homework Equations P=kV The Attempt at a Solution Why is it Pi / Vi and not Pf /...
  10. D

    Maximum compression in the spring

    Homework Statement Find the maximum compression in the spring, if the lower block is shifted to rightwards with acceleration of '##a##'. All the surfaces are smooth. Homework Equations $$\vec{F}=m\vec{a}$$ $$\vec{F}_{sp}=k\vec{x}$$ The Attempt at a Solution FBD of the upper block: From...
  11. S

    Does compressor efficiency account for intercooler energy costs?

    Hi all, I am looking at a air compressor train design which looks like this: I know how to work the compressor work needed for a two stage compressor, and hence how much work I can save using 2 instead of 1 stage. The question I have is: How much energy does it require to operate an...
  12. marcophys

    Calc L/min air compression to different pressures & temps in my compressor

    I have acquired a new compressor rated at 540 L/min @ 7 bar 150L tank I decided to test this at 23 degC, timing compression at 2 bar intervals (0-2, 2-4 etc.) I was surprised to find that it maintained 34 seconds at each interval up to 8 bar (but this could be poor experimental...
  13. P

    Isothermal compression and adiabatic expansion

    I want to know if a specific amount of gas has been compressed isothermaly an then released to expand freely, how much of the energy that has been spent on compressing the gas can be recovered. As for example, 1 gm-mole of Nitrogen has been compressed to 1/4th of its initial volume from at 1...
  14. P

    Isothermal (almost) compression of gas by water injection

    http://www.fluidmechanics.co.uk/ I have found this by searching net. The inventor claimed that by using a new kind of piston fitted with fins, he achieved almost isothermal compression and greatly reduced the power consumption process. I want to know how much theoretically sound it is.
  15. Wolfrider

    Traction/ Compression stress and strain exercise

    Hello everyone, could you help me with this exercise? I am stuck, and I can't find anything on the internet that solves this. Your help is very much appreciated :) 1. Homework Statement Circular steel bar, clamped at extremities. Two parts: A(ab)=800mm² A(bc)=400mm² L(ab)=...
  16. chad hale

    I would like to learn more about magnetic compression

    Hello everyone, I am chad hale. I am a student at Mesa Community College. I have learned that there is no insulation for magnetic lines of flux. I understand the Meissner effect; super cooled metals passing through a transition stage becoming super conducting. I understand that lines of flux...
  17. P

    Power needed for saturated steam compression....

    Want to discuss a matter here. If steam remains saturated during compression, how to calculate the power consumption for that by using steam table. Suppose, saturated steam has been compressed from pressure level A to pressure level B and it remained saturated during and after compression. We...
  18. C

    How Does Shear Stress in Beams Relate to Compression and Tension?

    Homework Statement In my notes , I was told that shear stress is maximum at the neutral axis . The normal stress will be maximum at one end , while the another end will be minimum... Homework EquationsThe Attempt at a Solution Why the shear stress is maximum at the neutral axis ? When we...
  19. C

    Do torque values equal compression

    Greetings All, We have a stack of parts which needs to have the height measured with 100 lbs of force applied. The plan is to put the stack in a vise and, using a torque wrench, tighten to handle to 100 ft/lbs. This doesn't seem right to me. Will 100 ft/lbs of torque equal 100 lbs of...
  20. P

    How to calculate the power consumption during steam compression

    Being a man who learned physics in college, I have tried to calculate that in the simplest way. As for example, if we need to know the power consumption to compress steam from 50C saturated pressure level to 1 bar i.e. 100C saturated pressure level, the best way is to know the gross enthalpy of...
  21. Kloud

    Spring compression after bullet passes through block

    Homework Statement Its in the screenshot i took. I need someone to walk me through the process of solving this problem because I do not understand how to get the maximum compression distance x of the spring. I know that the momentum of the billet will= the momentum of the block. Homework...
  22. E

    Isothermal Compression of a Ideal Gas and Distance

    Homework Statement The figure at the bottom shows a cylindrical tank of diameter D with a moveable 3.00-kg circular disk sitting on top. The disk seals in the gas inside but is able to move without friction. The gas inside is at temperature T. The height of the disk is initially at h = 4.00 m...
  23. P

    I Cylinder Compression: Pressure & Temperature Change

    Hello, according to thermodynamics the compression of a cylinder can both increase pressure and increase temperature. Unfortunately there is no law that gives us boh presure and temperture change given the change of volume, previous temperature and previous pressure? Usually we do either assume...
  24. S

    Entropy Change - Irreversible Isothermal Compression

    Given a sample of nitrogen gas (assume ideal gas conditions), the following conditions were observed inside the container. n = 0.75 moles at 253 K, and pressure = 0.5 atm. Then, an ISOTHERMAL IRREVERSIBLE COMPRESSION on the system forced by a constant Pexternal = 10 atm reduced the initial...
  25. S

    Conformability elastic material compressed on a wavy surface

    Hey there, I'm struggling in finding the useful equations to determine some conformability parameters for a finite elastic material (EPDM) compressed on a rigid slightly wavy surface. I would like to optimize the thickness of the elastic material in terms of indentation depth and thus contact...
  26. W

    Compression of an object and its length.

    I have heard a claim that looks a little odd to me and I am hoping that someone can help. In the gym there are foam rollers people use, some of them are 36 inches long and some are 16 inches. The claim is that the shorter ones can withstand greater weight than longer ones and will have less...
  27. Firasf1dream

    Effective Compression Ratio Definition?

    hello everyone, i would like please to know what is Effective Compression Ratio for an RC 2stroke Engine that i have ? the value in the info is 9.7, so i need to know the meaning and what values are the best ? what is the range ?
  28. S

    Decoupling Compression and Expansion of a turbine

    Hi, I just want to double check something: My understanding is that the higher the compression pressure the higher the amount of energy per unit mass it will take to compress a given mass of gas. So my question is, would a decoupled system where the compression can take place over a longer...
  29. G

    Compression load in jack stand leg

    If I have a jack stand that is essentially a tri-pod, with all legs at the base equidistant from the center tube, and a 36,000 pound load on the jack. What is the compression in each leg given these dimensions? My attempt: Each reaction in the vertical direction is 1/3 the load, and there...
  30. R

    Determine the compression in the spring

    Homework Statement A 1.2 kg glider moving at 3.0 m/s right undergoes an elastic head-on collision with a glider of equal mass...
  31. G

    Heating upon sudden elastic compression of material

    Hello, I would expect the heating of an elastic material upon sudden elastic compression to be given simply by the first law of thermodynamics, i.e. Delta Q=Delta U + P Delta V where P is constant since the compression is applied suddenly as in a square-wave pressure pulse (this is equivalent...
  32. Dietrichw

    Static equilibrium, tension and compression

    Homework Statement The figure below shows a light truss formed from three struts lying in a plane and joined by three smooth hinge pins at their ends. The truss supports a downward force of = 1 330 N applied at the point B. The truss has negligible weight. The piers at A and C are smooth. The...
  33. Behrouz

    How does the neutral pressure inside a balloon affect its lifting force?

    Hello everyone, Following Buoyancy formula, how much helium is required to help someone with 80 kg weight against gravity? While the Buoyancy depends on volume, what happens if we compress helium? Thank you in advance. Regards, Behrouz
  34. G

    High-pressure compression of liquids

    Hello, My memories of fluid mechanics are very rusty and therefore I was wondering if you could help me with this hypothetical problem. Let's say I want to generate very high hydrostatic pressures in a liquid (of order of 400 kbar). Would it be enough to do the following: take a rod weighting 1...
  35. G

    How to calculate compression of a spring

    centrifugal force apply force to spring while it spinning, how to calculate it's compression. there is no any attached mass on spring. just centrifugal force depends on RPM. weight of spring is important, centrifugal force is changing by radius, so it's not uniform.
  36. I

    Ph diagram for a vapour compression cycle

    Homework Statement Homework Equations N/A The Attempt at a Solution I am trying to understand the above ph diagram (for a vapour compression cycle), In some examples, point 1 is situated as above in the image (i.e. to the right of the saturated vapour line) and at other times it's situated...
  37. R

    Spring Compression: Homework Solutions

    Homework Statement Homework Equations ΔUelastic = 1/2(kxf2) - 1/2(kxi2) ΔK + ΔUg + ΔUelastic = 0 The Attempt at a Solution a) I used ΔUelastic = 1/2(kxf2) - 1/2(kxi2) and found xf - 0.126 m. b) Should I use ΔK + ΔUg + ΔUelastic = 0? I am unsure where to start for this one. How do I go about...
  38. R

    Spring compression of a bowling ball

    Homework Statement A 5 kg bowling ball moves at 10 m/s on a flat and frictionless surface. It hits a massless bumper with a spring constant of 100 N/cm. How far (in cm) will the spring compress? Homework Equations |F| = |kx| Fnet = ma The Attempt at a Solution This is mostly a plug and chug...
  39. grandpa2390

    How much work is done by the Adiabatic Compression of Diatomic Gasses

    I apologize if my questions were in the wrong place. I am in "Advanced" Physics Classes. And so I post the questions from those classes in the Advanced Physics forum. And these are questions that weren't covered in Introductory Physics (1st three semesters). But they keep being moved to this...
  40. grandpa2390

    What is the volume of the gas after adiabatic compression

    Homework Statement 1 liter of ideal diatomic gas (allow for rotation but not vibration) at a pressure of 1 atmosphere and a temperature of 300 K is compressed adiabatically to a pressure of 7 atm. What is the volume of the gas after compression? Homework Equations PV=NKT PV=nRT ##U_T##=f/2*NKT...
  41. N

    Time required for recovery from compression

    Hello everybody, As a university project, we are designing an electronic device in which the output depends on the current thickness of a thin polymer layer (typically around a few microns) which is subject to different levels of pressure and thus different levels of compression. I am...
  42. avito009

    Relation between compression and strength

    Whats the relation between compression and strength? When we build a structure, the ground or the land underneath the structure gets compressed and becomes rock solid. So how does compression make a substance strong? Is a compressed substance having more tensile strength?
  43. Eva001

    Max Spring Compression and Object Velocity on Frictionless Ramp

    Homework Statement An object of mass m = 2kg is relesed from a height h=5m and left to slide on a frictionless curved ramp. Once it reaches the bottom it slides horizontally from point A to point B, covering a distance L=6m on a surface with kinetic friction coefficient...
  44. Rx7man

    Centrifugal compressors, adiabatic compression

    Homework Statement I am working on creating a spreadsheet where you can input the parameters of an engine at a given rotational speed such as volumetric efficiency, boost pressure, atmospheric pressure and temperature, and compressor efficiency... It's been a very long time since I've done...
  45. Titan97

    Find the change in temperature during adiabatic compression

    Homework Statement Homework Equations $$PV^{\gamma}=\mathrm{constant}$$ The Attempt at a Solution Initially, the piston will get a velocity ##v##. But the chamber will move too because of the forces exerted by the gas. Since total external force is zero, velocity of centre of mass is...
  46. B

    B "Gravitational Compression in Neutron Stars"

    What happens to the neutrons in a neutron star as it collapses Into a black hole?
  47. M

    Tensile and compressive forces

    Example of a tightrope walker: Now, the weight force acts at a point. The rope is stretched. Compressive forces act inwards towards that point (opposite to TL and TR, the tensile forces). The resultant of the compressive forces equals the weight and is in the same direction – the weight force...
  48. M

    Zipgenius compression program, command line options

    I'm trying Zipgenius because it has excellent reviews from many sources, and it is free. The problem is, I can't find any documentation at all. In the program and on the official web site, the FAQ and Help links go to dead web addresses. In particular, I would like to know the syntax to zip and...
  49. S

    Absolute compression = true randomness?

    So I've read from various places that maximal compression produces a truly random output. But suppose you were going to apply compression to a truly random series of numbers with something like LZW. Well wouldn't it be the case that since randomness often produces sequences which do not appear...
  50. V

    How to identify members in a truss as compression or tension?

    Homework Statement Is this correct? The sum of the forces in the Y have to be zero and there is only two y-components so it's pretty simple to determine this. There are also only two x-components so those will also cancel each other out as they have to go in opposite directions to balance as...
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