This video was used to calculate the nominal steady state velocity of a 93 foot long piece of bead chain as it siphoned out of a 9 cm tall glass.where the middle of the pile had a height of 1.53 meters. The markers on the chain were .5 meters apart and the frame rate of the video was 300 fps. The chain had a measured mass of .551 Kg so its linear mass density was .0194 kg/m.
The tangles cause some variation in the velocity measurements (especially at the beginning of the video) but the average velocity after the nominal levitation height of .22 meters was produced was 4.3 m/s.
V=sqrt((H+2*h)*g)/2) gives a predicted value of 3.1 m/s as estimated in the Emperical Zeal site.
V=sqrt((H+6*h/5)*g) gives a predicted value of 4.1 m/s. using the equation given in the McDonald paper at:physics.princeton.edu/~mcdonald/examples/chain.pdf
v=sqrt(rho_l*H*g / (1-1/6)) value estimated in the Biggins and Walker paper at:arxiv.org/abs/1310.4056
for alpha=1/6 beta=0 and height of 1.53 meters results in a predicted value of 4.0 m/s
The free-fall impact velocity of a point mass dropped from a height of 1.53 m would be 5.48 m/s. Thus the measured K.E. was around (4.3/5.48).^2 (61%) of the max expected value which is very close to the 62.5% value given in the McDonald paper. That gives an energy loss of around 39% due to inelastic collisions and tangles that occur as the chain is pulled from the pile.