Flow Simulation Of Pipe Using Solidworks

Flow Simulation Of Pipe Using Solidworks

Aim:- To perform flow simulation of pipe to calculate flow at different velocity and Reynold's Number

Theory:-

Pipe flow, a branch of hydraulics and fluid mechanics, is a type of liquid flow within a closed conduit (conduit in the sense of a means of containment). The other type of flow within a conduit is open channel flow. These two types of flow are similar in many ways, but differ in one important aspect. Pipe flow does not have a free surface which is found in open-channel flow. Pipe flow, being confined within closed conduit, does not exert direct atmospheric pressure, but does exert hydraulic pressure on the conduit.

Not all flow within a closed conduit is considered pipe flow. Storm Stever are closed conduits but usually maintain a free surface and therefore are considered open-channel flow. The exception to this is when a storm sewer operates at full capacity, and then can become pipe flow.

Energy in pipe flow is expressed as head and is defined by the Bernoulli's Equation. In order to conceptualize head along the course of flow within a pipe, diagrams often contain a hydraulic grade line (HGL). Pipe flow is subject to frictional losses as defined by the Darcy-Weisbatch.

The behaviour of pipe flow is governed mainly by the effects of viscosity and gravity relative to the inertial forces of the flow. Depending on the effect of viscosity relative to inertia, as represented by the Reynold's number, the flow can be either laminar or turbulent. At a below the critical value of approximately 2040 pipe flow will ultimately be laminar, whereas above the critical value turbulent flow can persist. In addition, the transition between laminar flow and turbulence can be sensitive to disturbance levels and imperfections.

Flow through pipes can roughly be divided into two:

• Laminar flow
• Turbulent flow

Reynolds Number:-

The Reynolds number (Re) is an important in fluid mechanics used to help predict flow patterns in different fluid flow situations. At low Reynolds numbers, flows tend to be dominated by laminar (sheet-like) flow, while at high Reynolds numbers turbulence results from differences in the fluid's speed and direction, which may sometimes intersect or even move counter to the overall direction of the flow (eddy currents). These eddy currents begin to churn the flow, using up energy in the process, which for liquids increases the chances of cavitation. The Reynolds number has wide applications, ranging from liquid flow in a pipe to the passage of air over an aircraft wing. It is used to predict the transition from laminar to turbulent flow, and is used in the scaling of similar but different-sized flow situations, such as between an aircraft model in a wind tunnel and the full size version. The predictions of the onset of turbulence and the ability to calculate scaling effects can be used to help predict fluid behaviour on a larger scale, such as in local or global air or water movement and thereby the associated meteorological and climatological effects.

With respect to laminar and turbulent flow regimes:

• laminar flow occurs at low Reynolds numbers, where viscous forces are dominant, and is characterized by smooth, constant fluid motion;
• turbulent flow occurs at high Reynolds numbers and is dominated by inertial forces, which tend to produce chaotic eddies, vortices and other flow instabilities.

The Reynolds number is defined as

{\displaystyle \mathrm {Re} ={\frac {\rho uD}{\mu }}={\frac {uD}{\nu }}}

where:

• ρ is the density of the fluid (SI units: kg/m³)
• u is the flow speed (m/s)
• D is the diameter of the tube (m)
• μ is the dynamic viscosity of the fluid (Pa·s or N·s/m² or kg/(m·s))
• ν is the kinematic viscosity of the fluid (m²/s).

Objective:-

To calculate velocity and flow at different position and changing reynolds number with respect to time.

Steps:-

1. Draw a circle of o.15m radius on front plane sketch
2. Extrude the circle upto 0.5m
3. From top plane sketch draw three lines at a distance of 0.075m (85%),0.05(90%),0.025(95%) from outer face.
4. Click on flow simulation then select wizard and click on next and complete the wizard of creating a project.
5. Define boundary condition i.e. inlet velocity, Static pressure at outlet, Real wall to remaing portion of pipe.
6. Run the simulation
7. Go in results and make three cut plots at 0.075m,0.05m,0.025m.
8. Create parametric study of pipe and give it a name add cut plots and design templates with different velocity having reynolds number 10,100,1000
9. Run from scenario.
10. You will get the png images of result plots.

Calculation:-

Length of pipe:- 0.5m

Diameter of Pipe:- 0.30m

85% of length of pipe:- 0.075m

90% of length of pipe:- 0.05m

95% of length of pipe:- 0.025m

Velocity calculation using Reynolds number:-

Re=100, V=0.004m/s

Re=1000, V=0.04m/s

Re=10000,V=0.4m/s

Parts (Pipe):-

Scenerio of Parametric Study

Parametric Design till 85% of pipe:-

For Velocity 0.004m/s

Velocity 0.04m/s

Velocity 0.4m/s

Parametric Design till 90% of pipe:-

Velocity 0.004m/s

Velocity of 0.04m/s

Velocity of 0.4m/s

Parametric Design till 95% of pipe:-

Velocity 0.004m/s

Velocity 0.04m/s

Velocity 0.4m/s

XPlot of pipe:-

Explaination:- In this plot the velocity increases till a peak point then it starts decreasing gradually for XPlot

YPlot of pipe:-

Explaination:- In this plot the velocity increases till a peak point then it starts decreasing gradually for YPlot

ZPlot of Pipe:-

Explaination:- In this plot the velocity increases till a peak point then it starts decreasing gradually for ZPlot

Velocity Comparison Plot:-

From Velocity Comparison we can get that velocity is uniform as it is a laminar flow and It increases till a certain point and then starts decreasing gradually.

Conclusion:-

It can be concluded that the velocity of flow changes as the reynolds number increases and from the results it can be said that velocity first rises suddenly to a point and then decreases gradually.