Edinburgh Napier University

  This paper addresses discrepancies between the results of different measurements of the effective tensile strength F(F c ) of liquids, in experiments in which a pulse of tension (or ’negative pressure’) is created by the reflection of a pressure pulse at a suitable boundary. We show that a key feature of the pressure records previously reported in experiments such as the ‘Bullet-Piston’ (B-P) pulse-reflection apparatus [1] may have been misinterpreted. The first complete account of such pressure records is reported here. We also report a new method of estimating F e in a modified B-P apparatus and the results obtained indicate that samples of degassed, deionised water can sustain tensions which are an order-of-magnitude greater than previously reported in B-P work. Results are also reported for work involving samples of Newtonian silicone oils, for which the dependence of F c on shear viscosity, μ, found in this work confirms that of an earlier study although the absolute values of F c are found to be considerably greater than previously reported.