coefficient

  1. C

    W shape guardrail stiffness coefficient of friction

    Hello to all; I am new to this forum and in need of some help - please I am in the state of Florida where the DOT uses W shaped Guardrail and am looking for help in determining the guardrail stiffness coefficient of friction from a 30 degree offset crash impact. The result of the impact was...
  2. Screwed

    Coefficient of performance (COP) of this triangular cycle

    I have this problem: (it is not triangular really, just 3 steps in a closed system) Here's my solution attempt: NOTE: Evolution 2 to 3 is really an isothermic process, but in the diagram shows as an politropic process. So... But it isn't giving me logical values of COP when I compare...
  3. I

    Calculating Flow Coefficient

    Hello, I need help calculating the flow coefficient through a pressure reducing valve DN20. The values I currently have are: Inlet Pressure: 5 bar Outlet Pressure: 2.75 bar Flow capacity: 322kg/hr According to this website below, the density of steam at 5bar is 2.667 kg/m3 Saturated...
  4. P

    Film condensation heat transfer coefficient on helical tube

    Hi guys, I am working on my final year project and struggling to calculate the film condensation heat transfer coefficient on the my condenser. All I could find was the heat transfer coefficient on both vertical and horizontal plates and tubes. I can't seem to find h for helical tube that is...
  5. P

    Condensation heat transfer coefficient on helical condenser

    Hi guys, I am working on my final year project and struggling to calculate the film condensation heat transfer coefficient on the my condenser. All I could find was the heat transfer coefficient on both vertical and horizontal plates and tubes. I can't seem to find h for helical tube that is...
  6. G

    Integral coefficient for internal energy of ionic liquid

    I have a question, and I will be really grateful if someone helps me. I have a polynomial equation for internal energy which I calculated by integration an equation of state formula, which is based on density. But, because I calculated this using integration one integration constant which is...
  7. B

    Dittus Boelter M coefficient range

    Hello, I am doing Dittus Boelter correlation for Nusselt number accroding to my measured data. Coefficient (or constant) M that is related to Re has (in my case) value of 1.12. Is it physically possible to get value greater than 1? In my previous research, I've only met with a value of less than...
  8. E

    Coefficient of friction problem

    Hi everyone. I'm having trouble with a question and I was wondering if I can have some help? The question is: "The diagram shows a man of mass 70 kg at rest while abseiling down a vertical cliff. Assume that the rope is attached to the man at his centre of mass. You should model the man as a...
  9. L

    loss coefficient

    in the notes , why the author said when the inlet diameter equals to the outlet diameter , the loss coefficient can be determined? if the inlet diameter not equal to the outlet diameter , the loss coefficient can't be determined?
  10. L

    loss coefficient

    i cant understand why the author wrote that the loss coeeicient (including the friction factor) tend to be independent of the Reynold number at the large Reynold number , why ?
  11. L

    coefficient of volume expansion of ideal gas

    why the coefficient of volume expansion of ideal gas is given by the formula = 1/T ? by saying it = 1/T , the assume delV / V amd delP / P = constant ? why ? when the temp change , the density and specific volume(v) also change , right ?
  12. M

    Finding the coefficient of friction

    Ok. This is the verbatim problem: A skateboarder is trying to take a sharp turn (radius of 1.2m). She grabs hold of a tree branch to help make the turn. She pulls with 45 N of force. If she makes the turn going 3.2 m/s, what is the coefficient of friction between the wheels and ground. The mass...
  13. L

    determine the force involving static coefficient

    A force P acts as shown on a 200kg block placed on an inclined plane. The static coefficient of friction between the block and plane are Us= 0.5 . Determine the force of P to ensure he block is in the verge of moving down. The ans given is P = 560.4 N i have done in 2 ways , but my ans is...
  14. B

    Forces and Tension- given coefficient of friction to find speed?

    Okay, I've posted a lot, but this is the lat problem I'm having an issue with. Here I go! i) I have absolutely no idea. I can't even attempt because I honestly don't know what to do or where to start. How the heck am I supposed to find speed with what's given? It's not like I have time or...
  15. J

    Friction coefficient and slope

    I have problem with determining the friction coefficient. On the slope the weight of an object is divided into components: the force parallel to the slope and the force perpendicular to the slope. Force of friction is equal to the friction coefficient times the perpendicular force and force that...
  16. C

    Coefficient of velocity

    Hi there! I have done an experiment to calculate the coefficient of velocity of a jet flow through an orifice, and I got results with an interesting pattern. So I have done the experiment with two different heads and orifice sizes and got the following results for the coefficient of velocity...
  17. G

    Drag force coefficient difference in water and air

    Hi The density of water is 1000 but for air is 1.But in most of tables, the drag coefficients of the shapes are same regardless of the fluid around that.For example Cd around cylinder is about 2 for some specific reynolds, and we cannot see the Cd of 2000! I would appreciate if somebody clears it.
  18. W

    Coefficient of linear expansion question

    Measurements of XRay scattering from an unidentified metal are made. The bragg peaks are θ = 50° and 46° for temperatures of 299K and 1250K respectively. Calculate the linear expansion coefficient of the metal. This is given by (1/L)(dL/dT) The rate of change isn't uniform, so the...
  19. S

    How to find fk if there is no coefficient given?

    How to find fk if there is no coefficient given?
  20. E

    Drag coefficient changes with?

    Hello, I need some quick help. Does the drag coefficient of an object change when the volume changes? The mass density remains the same. Thanks!