# Calculating External Flow around a Sphere in SOLIDWORKS

Following the tutorial video above, we’ll run a 2D analysis with a very low Reynolds number in SOLIDWORKS, to see if we can emulate a creeping flow or a stokes flow – where the downstream flowlines mirror the upstream flowlines.

To do this, we’ll first need to switch to the “Configurations” manager and switch to the 2D Reynolds number one configuration.

On the Flow Study tree, we’ll name the project “Re = .01”.

Before we can run the study, we’ll have to adjust a few parameters. We’ll start by right clicking “Input Data” and select “General Settings.”

First, for a Reynolds number this low, we’re going to have to assume that the flow will be completely laminar, so when we adjust the fluid properties, we’ll switch it from “Laminar and Turbulent” to “Laminar Only.” We also have to adjust the initial and ambient conditions to account for the Reynolds number. We’ll edit the dependency for the velocity in the “X” direction and change the Reynolds number term from “1” to “.01” and accept the changes. We’ll also have to edit the equation goal to reflect the new Reynolds number. We’ll again change the value from “1” to “.01” and accept. Now, we can run the study.

When the solver finishes, we can close it and take a look at the cut plot. Here, we’ll choose “Contours” and “Vectors,” using the velocity in the “X” direction for contours and the velocity again for the vectors.

Looking at the plot, we can see that under these flow conditions, the upstream and downstream flows are very symmetric around the sphere. The wake behind the sphere expands slightly, but this could possibly be because the sphere is located slightly toward the front of the computational domain.

We can also see the change in the results for the goal plots, but remember, because of the 2D computational domain the values aren’t accurate. However, comparing these results to the Reynolds number one results, we can see that the drag coefficient is much higher here than with Reynolds number one.  