Recent content by FluidDroog

  1. FluidDroog

    Gas conductance through tube at low pressure

    Hi There! This is a super fun problem. Are you still looking for help? Check out the PDF by Genick Bar-Meir, "Fundamentals of Compressible Fluid Mechanics" Let me know if you need help.
  2. FluidDroog

    How Do You Calculate Static Pressure Drop in a Laminar Flow Channel?

    Hi Darcy30, Was it intentional that your username would hint at the solution? I understand the problem as follows: Assume laminar, steady state, constant density (incompressible), fully developed flow. Channel Geometry and Fluid Properties are known (I will assume the channel is circular) The...
  3. FluidDroog

    The Traditional Bernoulli Eqn Derivation of Rocket Exhaust Velocity

    Hi Brandon, Let me give it a shot. Bernoulli's equation is a conservation of energy statement for fluids. The write up in reference [1] is quite good and brief. Take a look at the list of assumptions needed to achieve such a beautifully simple (and powerful) equation. Many textbooks are...
  4. FluidDroog

    Undergrad Compressible choked gas flow through an orifice -- Excel formula

    Hi Stuart, Let's get to the bottom of this. Perhaps a unit conversion problem here. At a P of 301 Bar (30.1 MPaA), rho = 46.01 kg/m^3, engineering toolbox has a good write up on this [1]. Using the correct density values in your spreadsheet, I compare the sonic output to Lenox Laser's orifice...
  5. FluidDroog

    What Is the Best Method to Calculate Gas Flow Through an Orifice?

    Hi, I use the LenoxLaser calculator for orifice flow approximations when I need something fast. I agree with you that their explanation is bit underwhelming [1]. From that I assume you are interested in details and accuracy. The ISO standard for flow rate through orifices is ISO 5167-2. The...
  6. FluidDroog

    Find hole size for allowable leak in pressure vessel

    I understand the Problem as follows: The sealed volume is estimated to have a leak of 1 sccm of Air. The leak flow channel is assumed circular. The upstream pressure of the flow channel is 8"water column (8psig = 156.5 kPaA). The donstream pressure of the flow channel is 0" water column (0 psig...
  7. FluidDroog

    Convert mg/s to SCCM (Standard Cubic Centimeters per Minute)

    Hi, BvU is correct. To derive the relationship of cubic centimeters to 'standard' cubic centimeters of gas, you use the gas law equation of state. Standard means Ps= 101325 Pa, Ts = 273.15 K and Zs = 1. The derivation from reference [1] below should be sufficient to explain. It is a matter of...
  8. FluidDroog

    Convert Mass Flow Rate to Molar Flow Rate

    You should use the standard ideal molar volume to convert the flow rate from molar units to standard cubic centimeters per minute (sccm). The standard conditions are defined as P= 101325 Pa, T=273.15 K and Z=1. https://physics.nist.gov/cgi-bin/cuu/Value?mvolstd|search_for=molar+volume From...