The one thing I didn't get is that the drift maximisation should occur when the boundary layer separation distance is maximum between both sides of the ball from each other, so it should be somewhere close to the top spinner, but in practice it is closer to the square spinner. So maybe the optimal width of wake formation and resultant reaction force is dependent on maximising the horizontal distance between both points which occurs closer to the square seam/rifle spin seam?
Another thing that can be inferred is, does this necessitates the seam to be upright and there wouldn't be much drift on the scramble seam even if the rotational axis is kept the same as Lyon's. Unlike for dip?
I agree. Top spinner, with seam near the front and rear of the ball, at say 20degrees seam angle, will behave like conventional swing (though at lower Reynolds number) - this often gets referred to as an arm ball. To get the seam to directly separate the boundary layer, we think the seam has to be close to the "shoulders" of the ball, i.e. at seam angle 70 or 80degrees. We're running wind tunnel tests to try to understand this further as it is just an hypothesis at the moment.
For the scrambled seam there is another story, closely linked to baseball aerodynamics, which we are also hoping to prove or at least understand better, with experiments in our tunnel.
so if magnus doesn't explain drift of a spinner, how did Kuhnemman got reverse drift when operating at higher speeds?
The one thing I didn't get is that the drift maximisation should occur when the boundary layer separation distance is maximum between both sides of the ball from each other, so it should be somewhere close to the top spinner, but in practice it is closer to the square spinner. So maybe the optimal width of wake formation and resultant reaction force is dependent on maximising the horizontal distance between both points which occurs closer to the square seam/rifle spin seam?
Another thing that can be inferred is, does this necessitates the seam to be upright and there wouldn't be much drift on the scramble seam even if the rotational axis is kept the same as Lyon's. Unlike for dip?
I agree. Top spinner, with seam near the front and rear of the ball, at say 20degrees seam angle, will behave like conventional swing (though at lower Reynolds number) - this often gets referred to as an arm ball. To get the seam to directly separate the boundary layer, we think the seam has to be close to the "shoulders" of the ball, i.e. at seam angle 70 or 80degrees. We're running wind tunnel tests to try to understand this further as it is just an hypothesis at the moment.
For the scrambled seam there is another story, closely linked to baseball aerodynamics, which we are also hoping to prove or at least understand better, with experiments in our tunnel.