Recent content by jrmichler

  1. J

    Guidance for using mica strip heaters

    In order to heat the aluminum strips to 750 deg F, the heater will need to be at a higher temperature. How much higher depends on design details, but I suggest using a design temperature at the heater of at least 900 deg F. I do not advise steel HVAC duct. That material is zinc plated...
  2. J

    My glasses are giving me a neck cramp

    After I had cataract surgery, I experimented with reader glasses from the rack at the pharmacy. The +2.5 worked for normal reading, and +1.5 worked for my computer monitor. The +1.5 glasses did not work for reading. Then I got an eye exam with a prescription for bifocals. The distance...
  3. J

    Construction of a model of a hydraulic damper

    You have a hydraulic circuit with a flow resistance in one direction, and a different flow resistance in the other direction. Try search terms valve Cv or flow coefficient to learn how these flows are handled in the real world. The Cv is found experimentally, although you are free to try to...
  4. J

    Construction of a model of a hydraulic damper

    Sure. But first, you need to show us exactly what you are trying to do. This requires a sketch. The sketch does not need to be a detailed engineering drawing. A simple pencil sketch that shows your concept is normally enough. Designs that look similar can have either laminar or turbulent...
  5. J

    Random Photos

    I used SMPlayer (https://www.smplayer.info/) to play this video mostly because it has good single frame capability. Single frame to a frame of interest, then screen grab using ALT-PRTSCN, paste into MS Paint, resize to 800 pixels horizontal, and save as JPEG. Side benefits include ability to...
  6. J

    Random Photos

    From a dash cam video taken 3/22/2023. I was dodging a flock of turkeys on the shoulder of the road, and one decided to fly up in front of me. The three photos are three consecutive frames at 30 frames per second. Close, but did not hit. There is an interesting difference between...
  7. J

    Construction of a model of a hydraulic damper

    It's not clear exactly what you are trying to do, but it sounds like you are simulating a damper, then using the results to derive a damping coefficient. If so, damping coefficients refer to systems where the damping force is a linear function of velocity. Search term damping coefficient leads...
  8. J

    Random Photos

    We had a snow storm with strong winds last weekend. The wind lined up perfectly with this cottage to snow in the front door and make a big snowdrift on the road. The plow pile from that snowdrift is right on their driveway. A town plow got stuck near my house. Cell phone camera, slightly...
  9. J

    Collection of Lame Jokes

    I once had an original GE data sheet for the Turboencabulator. Sadly, it got lost long ago.
  10. J

    Collection of Lame Jokes

    The word tactical has been overused to describe guns, gun accessories, clothing, and clothing accessories. But this, I believe, crosses the line into lame jokes: Plain ordinary Number 2 Phillips screwdriver bits in a hardware store.
  11. J

    Flow Rate impact due to thermocouple obstruction

    No rule of thumb, but here is how I would approach the problem of calculating pressure loss. 1) Thermocouples are normally in a thermowell. That well has a diameter and length. Calculate the Reynolds number from the thermowell diameter and fluid velocity. 2) Find the drag coefficient...
  12. J

    Hydrodynamics of modular sponsons for my new Jetskis

    So far, so good. Now I need to see a diagram of the hull with and without your sponsons. Search terms personal watercraft hull design found numerous images. At least one of those should be good enough to show your concept by screenshotting and loading into MS Paint.
  13. J

    Hydrodynamics of modular sponsons for my new Jetskis

    Welcome to PF. Your diagrams only show a slotted object sliding over a T-rail. That's not enough for me to help you. Before I can express any opinion on the value of your ideas, I need more information. 1) Are you attaching to an existing bracket? How is that bracket attached? What are the...
  14. J

    Undergrad What physics study path would help me answer my own hydraulics question?

    High school physics has everything you need except for fluid dynamics. Fluid dynamics is a third year engineering course. Lots of fun reading in between. Which leads to what @Baluncore said. I would have liked to say something similar, but his words are much better than anything I would...
  15. J

    Need advice and hints for working with helium

    Any valves should be bellows sealed to eliminate leaks past the valve stem. The image below is of a Swagelok bellows sealed flow regulating valve: The above valve is not the right valve for a shutoff application. It is the first diagram that I found in a quick search that clearly shows how...