[pdp.aero]

Hi there,

Please take a look at the attached picture and tell me how you would mesh this shape in a STRUCTURED way!

For some reasons not interested in unstructured approach!

Best,
Pay

image

[cnsidero]

Here's an example that I wrote about some years ago:

https://www.pointwise.com/theconnect...putations.html

[pdp.aero]

Originally Posted by cnsidero

Here's an example that I wrote about some years ago:

https://www.pointwise.com/theconnect...putations.html

Hi Chris,

Happy to hear from you here again.

Thanks for the link. I've done that multi-block structured grid around multi element airfoils a while back.

That wasn't my question. For the multi-element airfoil we are dealing with the area surrounding the slat and flap.

How would mesh inside the crescent shape in a structured way?

I am writing my grid code for the upcoming hi-lift workshop. Lots of work there.

At the leading edge, there are WUSS (wing under slat surface). This crescent shape is the left and right faces for the WUSS on outboard and inboard wing. Because we're interested in a very nice boundary layer block to predict the CL max precisely I need to mesh both faces in way that lets me to create high aspect ratio hexs over the wuss surface. I attached a picture that demonstrate the geometry better.

Tricky, both left and right faces have zero-thickness or sharp edges at both ends which makes creating the boundary layer block over the wuss kinda challenging. Other people worked around the sharp edges by simply adding thickness to the ends. Probably because they use automated surface mesh generator.

I wanna keep the sharp edges as they are in the provided CAD model and go as close as to the CAD model when creating the surface mesh.

To be honest I solved the problem. Parameterized the sharp edges based on the node distribution on the root connector. Do appreciate your comment.

Regards,
Pay

[cnsidero]

Oops my bad. Misinterpreted your request.

TBH, for these kinds of high-resolution simulations I don't understand the presence of sharp edges. They don't exist in reality and I know from experience that resolving trailing edges is a key aspect in accurate drag and acoustics predictions for aircraft. I haven't looked at the recent HLPW geometry but does it really include sharp edges?

[pdp.aero]

Originally Posted by cnsidero

Oops my bad. Misinterpreted your request.

TBH, for these kinds of high-resolution simulations I don't understand the presence of sharp edges. They don't exist in reality and I know from experience that resolving trailing edges is a key aspect in accurate drag and acoustics predictions for aircraft. I haven't looked at the recent HLPW geometry but does it really include sharp edges?

Couldn't agree more... In reality we do not have zero-thickness edges but we might have sharp edges and sharp edges are important in aerodynamics. Regardless of what we have in reality, in aerodynamics we must have a sharp edge to let Kutta condition be satisfied. Have done some CFD simulations though a while back to see how it affects the pressure coefficient over a supercritical airfoil and with a cut-off TE never could get the pick of pressure coefficient in comparison to experimental data for a 2D case.

I don't know if the geometry committee included this kinda sharp edges purposefully or not but there is an intersection between two surfaces that creates the sharp edges at the end of two faces of the wuss. Very phenomenal! Take a look at the attached picture!

In the current hi-lift workshop all TEs have thickness but in general, the whole geometry is a mess. I got kinda surprised with all the details included in the wing. It's not watertight and has several gaps. Nonetheless, the wuss intersection with wing's surface is a very interesting question for me and also there is a FSF bracket underneath the wing that has some similar intersection with the wing's surface. Haven't got to that part yet.