Vista Radial Turbine Design (RTD) Tool by Ansys

Hello, in our previous video we designed a radial turbine blade using ANSYS tools. We started out with the Vista RTD tool, then went through the blade design, blade gen tools, and then analyzed the solution with the TrueFlow folder. And looked at our design, seeing how it worked.

Now, I would like to take a closer look at the blade design tool, which essentially is a mean line 1D blade design tool. So, let's double click on it. As we've worked on it before, we have two sets of inputs. A key part is the operating system.

Operating conditions, where we define the incoming gas flow. In this case, because it's a turbine, there's hot combusted air coming in. The temperature, pressure, mass flow rate, and then we have control over the expansion ratio. It's a key part of our design, as well as rotational speed.

And also blade speed ratio is required. And then we need to define some efficiencies. We can just use correlations such as Schuhmann or Bates, as available. And some nozzle efficiency. We can use the fuel, select our working fluid properties, and some flow angles.

The other set of inputs are some limitations on the geometry. Like the shroud exit to inlet radius ratio or hub exit inlet ratio. Number of vanes for our design. Mean vane thickness at the exit. And then the axial length. One could use a correlation or specify it.

So, what I would like to do in this video is maybe start with these geometry changes and kind of see the impact. For example, an axial length makes sense. Currently, what you see is this blade shape. If we, say, went to about 35%, we'll hit enter.

If we do a calculate, it's going to very quickly calculate and come up with a new design. And what you've seen is the blade design got shorter and fatter. So, that's kind of what we have with the axial length. And then we can start with the final design.

So, we're going to start with the final design. Axial length impact. Clearances. We'll look at that later on, maybe. Let's look at the diameter impact. You know, that's probably easier to see. So, shroud to inlet radius. Let's make this real small and hit calculate.

And, you know, let's take a quick picture. Far domain, kind of, you know, keep here on the side we do calculate and see if it had a huge impact on the geometry and kind of generated the wrong looking turbine blade. So, probably a 70 to 80 range would provide a more reasonable shape.

Okay, so that's that impact. Let's look at the hub exit inlet ratio. The default is 0. 4. And again, let's do a calculate and see. Essentially, what it did is it pulled in the hub, making this distance shorter. So, this gives us a good idea of the geometric controls we have.

Now, I'm kind of curious about what happens if we change some of the operating conditions. Would our blade shape adjust accordingly to that? What's the impact, and how big is it? So, again, let's take a picture of our reference for reference shape and let's decrease the mass flow rate.

Say, maybe go to half the mass flow rate. If you do a calculate, it is going to change and it does have a significant impact. It looks like it made the whole blade shorter, not much thinner, but it definitely made it shorter and made the inlet a little smaller.

Okay, so let's go back to our baseline. Now, let's look at the expansion ratio. What if we go from 2.2 to 3? It seems like it didn't have much impact on the geometry. So, let's go back to our 2. 2. And as for rotational speed, let's go from a hundred thousand to maybe double it.

See what type of impact it's going to have on our design. It looks like maybe that was pushing it too much. Maybe let's go to a lower value, such as a thousand rpm. And that really had a big impact. It doesn't look like a reasonable figure for a turbine blade.

So, we're back to 100,000, back to our shape. And what if, you know, we had a very bad, or expected much worse, efficiency. Will that, how does that, you know, impact the general design? Let's see if we see anything.

So, it essentially wanted to make the inlet wider so it can compensate for that poor efficiency. So, let's go back to our value. Let's recalculate, and you can essentially see the nozzle inlet change a little bit. And I feel kind of curious about the inlet angle.

Let's do a zero relative inlet angle. Will that have much of an impact? It doesn't seem to. It probably had more of an impact on the velocity triangles, which is another set of results. So, let's go back. Let's turn this off. Let's do a recalculate.

And yes, we can, you know, essentially let's, save these. Okay. Put it on the side. Let's do zero inlet. Recalculate. Look at our velocity triangles. You know, you can see a little bit of a difference. It really did not have a very notable impact on the solution.

And that concludes my presentation on the blade design tool. Thank you so much for your interest. Have a good day. Thank you.