Reynolds Definition and 117 Threads

1.I have been asked to: Calculate the density of a fluid if a ctitical velocity of 2m/s at Re=2000 in a pipe of bore 90mm at a dynamic viscosity oc 0.09cP I have calcualted the variables to SI units and found \rho=? Um (V) =2m/s D=0.09m \mu=0.09X10^-3 I am rearranging this...

Hello, I am trying to obtain how to find the Reynolds Number of a circular plate perpendicular to external flow. Thanks

Hey guys, I'm looking for a little help understanding Reynold's Number. I know that its the ratio of the inertial forces versus the viscous forces. With that being said, everywhere I look, the Reynold's Number is calculated for flow in a pipe or duct or across some sort of surface. Why can't...

I want to know how Reynolds Equation of Momentum is accord with the 3rd law of Newton, the law of action-reaction forces. For an ideal fluid, we have that [tex] \frac {\partial m \vec {v}} {\partial t} = \vec v [ \frac {\partial {\rho }} {\partial t} + \nabla [ \rho \vec v ] + \rho [\frac...

Homework Statement Hi everyone, This problem concerns calculating Reynold's Number of flow after exiting a duct. The duct that the flow exits is rectangular. The flow is measured directly underneath the center of the duct at a distance of 10 cm below the exit (Y-axis). Flow is measured...

Are there any reference tables for what to use as the characteristic dimension of various shapes when calculating the Reynolds number? I am very interested in ballistics, and have done research and calculations for various ways of estimating the drag coefficient of various bullet shapes. I...

Hi I need a software for designing airfoil that alows changing the choard size and printing. If you know any please tell me. Btw do you know any refrence for low Reynolds number (about 50000)? I want to choose NACA7610 for my glider but I don't know exactly how it behaves at low Reynolds...

The question gives this .. The Reynolds number, Re, is a dimensionless group which characterizes the intensity of a flow. For large Re, a flow is turbulent; for small Re , it is laminar. For pipe flow, Re=u(density)D/mu, where D is pipe diameter and mu is dynamic viscosity. It asks ...

Hi all. Why Reynolds Analogy and other empirical relations always overesimate heat transfer? I have done an experiment on turbulent pipe flow (smooth pipe) and I used Reynold Analogy (both the simple (Pr=1) and the modified one) and the Dittus-Boetler correlation equation to do the...

The Reynolds Transport theorem (RTT) is usually applied to derive the conservation of mass, momentum and energy in a fluid. But when I try to apply the RTT to other physical quantities, I get weird results. Can anyone see where I'm going wrong? As a simple example, take the physical...

I understand most of the equation. [tex] Re=\rho *D *V over a symbol I don't recognize I don't know what the symbol is the denominator, and I can't find its name so I don't know what it means. I just need one definition, thanks.

Hi all! I am confused about the theorem quite much. The theorem says that the time rate of change of a property of a system is equal to the local rate of such property in a control volume plus the efflux of the respective intensive property across its control surface. I am wondering the...

How does one relate the Reynolds number to the Drag Coeffient? It seems the drag coefficient for different velocities must be determined experimentally per set. I know the Reynolds number is a method to determine laminar or turbulent flow, but can it be used to determine the drag coefficient?

I have come across the Reynolds Transport Theorm in my study of Fluid Dynamics, and it's a very powerful tool. \frac {DB_{sys}}{Dt} = \frac{ \delta}{\delta t} \int_{cv} \rho b dV + \int_{cs} \rho b \vec {V} \cdot \hat {n} dA Where B is any extensive property of the system, and b is any...

hai all, I'm now doing a research about castor oil. I've a got a few a confusing problems.. 1. to flow castor oil in a 12 mm acrylic pipe i use a reservoir 1 metres from the outlet. Because castor oil is very thick (dyn visc. = 0.5 Pa-m), the velocity of the flow is very low just about 0.02...

Is there some reason for Hazen-Williams friction model to failure in a hydraulic circuit?. I have simulated an hydraulic system in a commercial code, and this model is the unique which gives stupid results like infinite volumetric rates. The Reynolds is about 10^5.

Hi all! In a pipe flow, when the flow rate of water is increasing, reaching a critical flow rate, the flow will switch from laminar to transition flow, right? And continue the increase of flow rate will further change it to turbulent flow. The Reynolds number for these 2 transitions are...