A statistical model predicting the evolution of turbulent mixing zone front
s was developed recently by Alon et al. It suggests that the three physical
elements that govern the Rayleigh-Taylor and Richtmyer-Meshkov mixing zone
evolution are the single-bubble evolution, the single-spike evolution, and
the interaction between neighboring bubbles. In this paper we present an e
xperimental investigation of these three elements in the Richtmyer-Meshkov
case. The experiments were performed in a double-diaphragm shock tube. The
interface evolution was studied both before and after the arrival of a seco
ndary reflected shock. Experimental results for the single-bubble and two-b
ubble cases show distinct bubble and spike evolution. The results of the bu
bble competition, which determines the front evolution, were found to be in
good agreement with both full numerical simulations and a simple potential
flow model. These results strengthen the assumptions on which the statisti
cal model is based.