In preparation for a Fluid Mechanics experiment, I am looking for a simple commercial ready made apparatus to generate a linear velocity trend to prove a new theory:


The load is around 10kg starting from rest to reach linearly say a 0.5m/sec within a distance of say 0.5m.. Any hints ? :)

72nd Annual Meeting of the APS Division of Fluid Dynamics Volume 64, Number 13

The Leading Edge theory: a new insight into the laminar Boundary Layer by Mohammad Gabr

The Abstract :

The flow properties at the leading edge of a flat plate represent a singularity to the Blasius laminar boundary layer equations; by applying the diffusion equation where the velocity of a moving flat plate in a stationary fluid is diffused to the far field, the leading edge velocity profiles are studied. Experimental observations as well as the theoretical analysis show an exact Gaussian distribution curve as the original starting profile of the laminar flow.To conclude; the main key results are as follows: [1] The velocity profiles at the leading edge of a flat plate are Gaussian Curves that grow in space and time; whereas the Blasius velocity profile is a part of the general Gaussian curves solution. [2]A new method to calculate the friction drag is successfully tested, based on the displacement area of the leading edge velocity profile. [3] In order to obtain the final physical proof of the new theory it is recommended to carry out experiments using an ultra-thin flat plate moving in a stationary fluid and measuring the velocity profiles at the leading edge with different measurement techniques.

  • $\begingroup$ Welcome to engineering.SE! If the new theory for your experiment matters for the question, you should briefly summarize it in the text, since the link might at some point in the future get outdated. $\endgroup$ Apr 24 '20 at 20:16
  • $\begingroup$ Thank you for the advice ... well the link I believe is permanent as long as the AIP .. American Institute Of Physics Journals are permanent .. $\endgroup$
    – M Gabr
    Apr 30 '20 at 10:19
  • $\begingroup$ The AIP is likely permanent, the link might still change..my bank already changed the URL of their online banking twice, making my bookmarks invalid. Just a suggestion, it could improve the quality of your question and attract more helpful answers. $\endgroup$ Apr 30 '20 at 10:28
  • $\begingroup$ Please edit the question to add the info, don't write it into the comments $\endgroup$ May 1 '20 at 23:56
  • $\begingroup$ Why don‘t you buy a linear drive that has a Position /speed controller...they can be purchased or made readily. $\endgroup$
    – morbo
    Sep 30 '20 at 7:15

You could use some sort of rack and pinion (automotive maybe?)with a drive wheel on your pinion shaft... or attach an arm like a bike pedal to move it back and forth, the longer you make the arm the easier to pull but you must pull the longer distance. The theory your testing doesn't affect the question.

  • $\begingroup$ Well, thank you, but I do need a linear velocity over time trend in a specific way.. to compute the drag force, and I need to have the actual force exerted to compare it with the calculated .. actually, after a long search in the web, I was really surprised that such a simple equipment does not exist ..I wish i am mistaken .... $\endgroup$
    – M Gabr
    Apr 27 '20 at 0:40
  • 1
    $\begingroup$ Yes, I do not know what you would want to use for your control mechanism. A motor that you control the speed of with voltage seems the easiest to make. $\endgroup$ Apr 27 '20 at 2:33

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