Case of a non-peristaltic pump, like a pumping heart with check valves :
Math of the pump
Conclusion
The volume of water pumped per contraction is proportional to the square of the number of turn of Nitinol spring times its radius and proportional to the length of the pump.
To set the shape of the nitinol spring we "cook" it around a rod that's bent at 360°. Based on the radius of this rod, for a desired flow of water, we find the number of turn we need.
Ex :
rod : 4mm
Flow : 20L in 5 min
Contraction every 5sec (time for nitinol to cool)
length of pump : 10cm
N = 1/0.004 * sqrt( (0.02/(5*60)* 5) / (3.14 * 0.1)) = 9 turns
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