increasing quality of the play of both professional and amateur players has set
grounds for expanding the production of aids and accessories, such as tennis rackets,
for this game.
There is a wide variety of tennis rackets presently available on the market and
these could be basically assessed on the basis of the following characteristics:
1. Type of material used for manufacture
2. Size and dimensions of racket head
4. Racket weight
5. String tensioning
6. Degree of damping and vibrations
The first 5 characteristics are quantitative and could easily be determined and
controlled using common measuring equipment. The sixth characteristic, - vibration
resistance, is the appealing element. The value of these vibrations is important and is
hard to determine with formulas due to the complexity of the friction process, the
friction and the air resistance losses [2].
3. Equipment Rules for Tennis Balls
Tennis Ball data such as, the ball’s size, the ball speed and the rate at which the
ball spins have to be evaluated as well as other distinguishing shape features.
The tennis ball is roughly a 63.5-mm (2.5-inch) sphere. It has a uniform outer
surface, a continuous hourglass shaped seam and a felt-like fuzz. The ball has to be
white or yellow in colour. It has to be more than 56.7-grams (two ounces) and less
than 58.5-grams (two and one-sixteenth ounces) in weight. The average professional
tennis player serves the ball at 120kmph and the spin of the ball during a serve can
reach around 1000 rpm [2].
The seam of the ball is a very important issue to deal with. International
equipment regulations dictate for the minimum seams to appear in the surface of a
ball. Furthermore, these should be stitchless. The seam makes the surface of the
tennis-ball very porous and non-uniform.
3.1 CFD Seam Simulation
My interest on the seam feature and its consequences led me to start simulating
