Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

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

Search results for query: *

  • Users: mwemag
  • Order by date
  1. mwemag

    Solubility of gases in liquid metal

    Thanks, calculating with the atomic ratio seems indeed promising. But: "A dissolved gas in a solid is part of the solid, there is no remnant of the gas properties left." So the solution of liquid iron and dissolved nitrogen would form just liquid Iron nitride (FeN)? Is then the higher electric...
  2. mwemag

    Solubility of gases in liquid metal

    IRstuff, the primary goal is to aproximately estimate the increase of the specific resistivity of a metal in the liquid phase when a certain amount of a gas is dissolved in the liquid metal. The electric insulation strength of a gas is given by its low density, independent of its mass...
  3. mwemag

    Solubility of gases in liquid metal

    I am investigating the application of gases dissolved in liquid metals for increasing the electrical resistivity of a liquid metal-gas solution. Many data on the solubility of gases are often specified in weight percentages, (wt%). For example, the solubility of nitrogen in liquid iron at...
  4. mwemag

    Eddy current force amplification

    Eddy currents are induced in a nonferromagnetic piece of metal conductor, e.g. aluminium or copper, when it is placed next to a conductor with high frequency AC. A magnetic field opposite to the 1. field is produced in the metal, ("mirroring"), therefore producing a repulsive force, which in...
  5. mwemag

    Magnetic fields within hollow wires

    If you look at the simulation with a closer view (see the new attachment below) you can see that in the force display mode the white arrows are always ponting towards the center of the hollow conductor (you preferably open the image in full resolution to see the arrows). Despite the obvious...
  6. mwemag

    Magnetic fields within hollow wires

    sreid, the grafic simulation shows a force acting on the inner conductor (http://www.falstad.com/emwave2/index.html). All I know is that the force is either repelling or attracting, depending on the current flow direction, and that the force vectors are always concentric or excentric...
  7. mwemag

    Magnetic fields within hollow wires

    Yes,there will be no field inside the hollow conductor, except the field generated by the inner conductor. Actually, what I'm interested is to calculate the magnitude of the forces acting on the inner wire. The attached screenshot shows the absence of magnetic field within the hollow wire on...
  8. mwemag

    Magnetic fields within hollow wires

    Does anyone know a way to calculate the magnetic field acting on a wire, when this wire is placed in the center of a bigger hollow wire? I have the outer and inner diameter of the hollow wire, the diameter of the wire in the center (this two values define the radial distance between the...
  9. mwemag

    wire length versus energy consumption

    Very valuable answers, thanks to all!
  10. mwemag

    wire length versus energy consumption

    Yes, fluctuations of the voltage are very common. Additionally, halogen bulbs are sometimes produced to run underdriven to increase their lifetime, but at the price of reduced brightness and color temperature. Therefore exact values of power consumption will be easier to measure than to...
  11. mwemag

    wire length versus energy consumption

    dpc, let's assume that the lamp would be a low voltage halogen bulb, e.g. ratet at 60W and 12V, and that this rate corresponds to the voltage and current in the active state (including the losses by the increased resistance of the tungsten filament when heated). I don't understand much of...
  12. mwemag

    wire length versus energy consumption

    Thanks again. So, connecting a 60W-bulb to a wire descibed above will consume 65.5 Watts (theoretically). Correct?
  13. mwemag

    wire length versus energy consumption

    Just to be sure on the units: Watts = I²·r·D I=5 (amps) r=0.01724 (mm²·ohm/m) D=10 (meters) =5²·0.01724·10 =4.31 Watts Or do I have to adapt the effective diameter aerea (0.5mm·pi=0.785mm²) for the r value?
  14. mwemag

    wire length versus energy consumption

    Thanks. I assume the result will be in units of watts per second. Since I need to compare to the energy consumption of the original device in Watts (e.g. 60W), how to convert the watts per second to watts?
  15. mwemag

    wire length versus energy consumption

    I'm looking for a way to calculate the additional energy consumption of an electrical device, if the same current used for the device has to run through a wire with a given length, diameter and resistance, before reaching the device. As an example, take a lamp with an energy consumption of...
  16. mwemag

    Evaporation Preventing

    Thanks! I should have concentrated on psychometric descriptions much earlier... By putting "saturation quantity" into play, it was easy to do a simple demonstrative calculation with an astonishing result: The saturation quantity of water vapor in air at 95°C and normal atm. pressure is 961.88...
  17. mwemag

    Evaporation Preventing

    zdas04, actually the total gas pressure in the device will increase already because of the gas heated by the hot temperature of the fluid. The empirical value shows that the original pressure of the fill gas in the cold state at RT, around 5 atmospheres, will increase in the hot state to...
  18. mwemag

    Evaporation Preventing

    The total pressure of a gas mixture is always the sum of the individual partial pressures. If the original gas has a pressure of 1 atmosphere (?100 kPa) and the added vapor pressure (needed to establish equlibrium) is 85 kPa, then the total pressure is 185 kPa. Assuming now to increase the...
  19. mwemag

    Evaporation Preventing

    ...to integrate the total pressure factor into the calculation. The following formula for example is used to calculate the evaporation rate (in kg/m2*s): (vapor pressure - ambient partial pressure)*sqrt( (molecular weight)/(2*pi*R*T) ) vp =Pa, ambient pp = Pa, molec. w = kg/mole, R = universal...
  20. mwemag

    Evaporation Preventing

    "until the partial pressure of the vapor is equal to the vapor pressure of the gas at that temperature" For example, when I have water at constant 95°C with a corresponding vp of ca. 85 kPa and dry air as the initial fill gas in the container, having normal atmospheric pressure (100 kPa)...

Part and Inventory Search

Back
Top