How to calculate the Reynolds number for vortex flow meters

This post was last edited by Simply put_myP89 on 2021-9-4 at 15:17. The original poster asked two questions, but no one replied for an hour – there is a reason for that. 1. Re is five variables; knowing four of them allows one fixed value to be determined. Re=vd/γ=ρvd/η; it’s simple to see that you need to determine at least four values first: the average flow velocity, the inner diameter of the pipe, the dynamic viscosity coefficient, and the fluid density. However, it’s important to understand that the Reynolds number is a range, and it is only within this range that it can be determined whether the flow is laminar or turbulent. It depends; if the original poster has no experience with fluids, that’s okay. I’ll recommend a website that has calculators available, for reference only. The prerequisite is that you must first determine the four values; otherwise, it’s impossible to calculate. Formula for calculating the Reynolds number Re and online calculator _ Sanbei Calculation Network _ 23bei.com. 2. As for how this value is obtained, it results from calculations and unit conversions during the derivation process; you just need to know how to use it, without having to understand how it’s derived. I suggest the original poster not bother thinking about it and just use the formula directly; this involves the derivation of the entire formula, such as time-varying inertial forces, position-varying inertial forces, mass forces, viscous forces, and so on. I think the original poster doesn’t need to use their brain for this. I guess the original poster must be unwilling to accept it, and I’m really curious. Just find a derivation process online and pick out a small part of it; note that this is only a tiny portion. To be honest, I’ve long forgotten all the details; I just need to know how to use it. It’s enough to know when the flow is laminar and when it’s turbulent. We are in application, not research. As an extra note, there are many experts on the forum, including those who specialize in this area. When I was at Beihang University, there were people who focused on Re, carrying out various experiments and calculations. They are legends; we should just admire them. I’m just trying to stimulate discussion; I hope some expert can spare some time to provide a detailed explanation for the original poster. We are bricks; if there’s anything wrong, don’t throw us in the river, as it may cause corrosion.

Dude, you’re looking at page 89 of the book \"Instrumentation Test Questions Collection – Field Instruments\" (3rd edition). If you read it carefully, the answer is on page 59 of the original book. As follows:

I can only say, thank you so much! I need to understand vortex flow meters – I’m looking at vortex flow meters directly! I haven’t seen the part before, but thanks anyway!