Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  • Users: htsmech
  • Order by date
  1. htsmech

    Pressure drop over time

    I have a system that uses a bellows to pressurize air in a fluid reservoir with a small exit tube. I am trying to model the flow rate of the fluid over time. I am assuming PV=C, and that dV/dt=(P-Pa)*K, where C and K are constants. The air volume (including bellows) is large compared to the...
  2. htsmech

    Elongating light spot

    Duh! I will try illuminating it from the side. Thanks, Steve
  3. htsmech

    Elongating light spot

    I am trying to illuminate a surface with light from a light guide. At the distance I am using, the spot is 7mm dia, but the surface is 7x28. Can I use a plano-concave cylindrical lens to stretch the spot 4:1 in one direction? If so, how can I calculate the object distance given the focal...
  4. htsmech

    Definition of Terms

    Does anyone have a good definition of accuracy vs. resolution vs. repeatability? Thanks, Steve
  5. htsmech

    Why is stiffer better?

    Just a basic theoretical question (or three): I know that it is desirable to have the natural frequency of a system be far away from any driving frequencies. -Is there any inherent advantage to having the natural frequency above the driving frequency? If I look at an output magnitude vs...
  6. htsmech

    Piping size versus total output

    Lots of websites on this, here is one. http://www.efunda.com/formulae/fluids/calc_pipe_friction.cfm See the hint to calculate a flowrate below the inputs, or find a website that has a calculator that has output pressure as an input, or just use the equations to plug and chug. Good luck, Steve
  7. htsmech

    Change in tubing volume as a function of pressure

    As I mentioned in another thread, I am looking at a fluidics analogy of an RC circuit to filter out pressure fluctuations. The R is just a constriction, but the C has to be a "balloon", with a relatively linear change in volume vs. pressure. I am thinking of peristaltic tubing, but...
  8. htsmech

    Eliminating pump pressure fluctuations

    I am trying to eliminate pump pressure fluctuations in an analytical instrument. We have a few unique constraints. 1. The sensor itself is sensitive to ~.1psi fluctuations, and is at about .5psig 2. We are very sensitive to mixing of the sample fluid with the preceding buffer, so tees or...
Back
Top