A discussion on deformation of solids by the impact of liquids, and its relation to rain damage in aircraft and missiles, to blade erosion in steam turbines, and to cavitation erosion - The erosion of solids by the repeated impact of liquid drops

Abstract

An investigation of the erosion of solids by repeated liquid impact at relatively low velocities has been carried out. The work has shown that even at low velocities compressible behaviour of the liquid is important in determining the impact pressure. An attempt has also been made to determine the distribution of the impact load. The mechanism of erosion in brittle polymers and in ductile metals has been studied. The effect of altering the conditions of impact on the erosion behaviour is described.

Effects of pulsating water jet impact on aluminium surface

“…According to Hancox and Brunton (1966), the limit is given by v c 1 = sinˇ (6) whereˇis the liquid/solid interface angle-see Fig. 2.…”

“…If the surface is stepped or broken in any way, very large shear forces are produced by the impingement of the flow against the projections in the surface. The shear forces acting on a roughened surface are large enough to cause local shear fractures, even in high strength materials (Hancox and Brunton, 1966).…”

Use of Acoustic Waves for Pulsating Water Jet Generation

“…2 (Hancox & Brunton, 1966 At this stage there is a rapid fall in pressure along the periphery of contact. As the outward flow continues, the water-hammer compression at the centre of impact is relieved until the maximum pressure acting on the surface is the central stagnation pressure for the incompressible flow.…”

“…Therefore, there are additional shear forces associated with the high speed flow across the surface acting on the surface in addition to the normal forces. The shear forces acting on a roughened surface are large enough to cause local shear fractures, even in high strength materials (Hancox & Brunton, 1966). Exploitation of above described effects associated with water droplet impingement on solids in a high-speed water jet cutting technology should lead to considerable improvement of its performance, better adaptation to more and more demanding environmental requirements, and consequently to more beneficial use of the technology also from the economical point of view.…”

Effect of Droplet Diameter on Liquid Impingement Erosion

“…The volume loss per droplet increases with 4.67th power of droplet diameter. ．一方 Hancox と Brunton (3) は，0.4mm から 2.0mm までのジェット径を用いて PMMA(ポリメチルメタク Table 1 Chemical composition of test materials for rotating disk method (mass %) Table 2 Mechanical properties of test materials for rotating disk method Table 3 Chemical composition of test materials for high pressure method (mass %) 1.E-22…”