Giuseppe Pucci 1
Friction on water sliders
Giuseppe Pucci, Ian Ho and Daniel M. Harris
coil
electromagnet water
tank
magnet
slider
1 cm
slider
time sequence
0.5 1 1.5 2
0 5 10 15
Pucci G., Ho I. and Harris D. M. Sci. Rep. (2019).
Giuseppe Pucci 2 We define the sliding number
t
CL : time for the boundary layer to developt
dec : time of decelerationPucci G., Ho I. and Harris D. M. Sci. Rep. (2019).
m dU
dt = F
DS
l= t
CLt
dec= ⇢ m
r R
5⌫ U
F
D= ↵⇢ p
⌫ R
3/2U
3/2S
l⌧ 1
boundary layerlaminarFriction reduction
R = 4 12 mm m = 50 1350 mg
⌫ = 0.01 0.04 cm
2/s
1 2 3
0 0.2 0.4 0.6 0.8 1.0
modèle
dec
,
p
δ