Design methodology for under-slung store structure of air-borne Time Domain Electromagnetic (TDEM) system

Abstract

Time Domain Electromagnetic (TDEM) system is a rapidly developing area for geophysical surveying. It encompasses ground based and air-borne application. The present investigation aims at establishing a basic design methodology for the helicopter under-slung store structure that houses transmitter and receiver coils of the TDEM system. Based on the knowledge of dynamics of air drag and classical mechanics, a working model of structure has been proposed. There is hardly any straightforward methodology and guidelines available in the public domain for the structural analysis of the typical under-slung store structure for this application. Hence, an attempt has been made to make novel application of the more generalized aerodynamic theory. In this investigation various loading conditions under normal operations of air-borne TDEM system have been used. This includes air drag due to uniform forward flight in normal wind environment, drag during hover due to helicopter blade rotation, and self weight of the structure.