well, you can do a negative for the dimple and do a spherical pattern with the pattern command in 3D solids. You might have to get creative to take up all the empty spaces but that would be a starting point. Maybe do a pattern along projected curves on the sphere too.

maybe you can share your non-linear surface but I would make that into a solid to work with the pattern command.

so you want to dimple the inside of the ear cones? If so, you need to put a dimple to start.

Murray-

thanks for your input! where to I find the tool for invoking the isoline layout on the intake horn's surface. given a "wrapped" grid, I'll likely use the Powerpack tool for distance normal to a surface at a point to locate the center of the subtraction spheres.

the top level objective is getting more air into a carburetor. that implies using all the horn's area for air flow; ie: attached flow on the short side radius. dimples are an aerodynamic "trick" to convert laminar boundary layers to turbulent boundary layers which stay attached farther around a curved surface. it's why golf balls with dimples fly farther than spherical objects the same size and weight; less profile drag as a direct result of the turbulent boundary layer staying attached further. most introductory texts on fluid mechanics or aerodynamics are likely to have illustrations and further/better explanations of what's going on.

Art
[email protected]

Edited by user Friday, October 25, 2019 6:11:41 PM(UTC)  | Reason: Not specified

thanks for the pointer on isolines!! I'd never changed the zeros before so had never stumbled across the utility of the tool. is there any way to select a switch such that the isoline intersections become selectable?? the grid is outstanding but without a means to select the intersection of the vertical and horizontal lines I don't see how they can help me. cutting and fitting line segments to the surface is definitely doable, just a lot of work.....! line segments would be the enabling vehicle for arrays of equally spaced "points" on the surface of the horn(ie: equivalent to horizontal & vertical isoline intersections).

the reason you probably haven't seen dimpled surfaces on intake horns before is there are very few carburetors with siameased venturi. there is no need/value for dimples with straight elliptical horns. Weber 32/36 carburetors (ie: the one used in Formula Ford, Formula Continental, & Sports 2000) are one of the carburetors with the siameased "feature". to implement the geometry advocated by Prof. Blair & W. Melvin Cahoon in their paper "Best Bell", something other than two straight elliptical horns is required. the non-linear center line of the elliptical horns is the root cause of the resulting short side radius and the subsequent need for the dimples to maintain attached flow.

see custompolycast.com for an example of currently available dimpled intake horns.

Art
[email protected]

Edited by user Friday, October 25, 2019 9:22:33 PM(UTC)  | Reason: Not specified

rockyroad_us-

thanks for the input! where/how do I change the object type? assume you have a slow student......

Art
[email protected]

Murray-

thanks! unfortunately I'm still doing the two steps forward followed by one step back game...... changing the object type also changes the grid spacing?? I've confirmed after chancing the object type the grid vertices are selectable which is major progress. now the question is how to maintain control of the grid spacing; it's critical for imposing the desired dimpling pattern uniformly onto the surface. see attached image below.

Art
[email protected]

Not sure how the additional iso lines are changed. I didn't get that result. see picture.

Maybe that's version dependent. I'm on a mac.

Good going, Art. If it ever gets on a dyno, show off the results to us?