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 - Practical aspects of rain erosion of aircraft and missiles

Abstract

All-weather operational requirements have added considerably to aircraft and missile design problems as the effects of various meteorological hazards, predominantly rain, are aggravated by high speed flight. Typical damage patterns are reproduced and discussed. The problem of rain erosion is reviewed with regard to the functional requirements of the components, the flight plan of the vehicle and the occurrence of rain over the geographical terrain of operation. The factors affecting rain erosion characteristics such as type of material, surface finish, shape of component, speed and rainfall intensity are discussed and empirical data derived. The translation of significant results into practical applications is described with particular reference to supersonic transport aircraft. Details given of equipment for the simulation of rain erosion are concerned principally with the R. A. E. ‘whirling arm’ and rocket runway high speed sled techniques. Correlation of test results from these facilities with those from flight tests are briefly discussed. Degree of erosion of a material is defined in relation to the particular application of the material and details are given of the characteristics of numerous materials, both metals and non-metals. The utilization of these materials for such applications as radomes, transparencies, high temperature materials, de-icing systems are briefly discussed together with methods of extending the rain erosion ‘life’ of materials by design or by use of protective coatings.