Code_to_Code Comparison on Pre-Test Aerodynamic and Aeroacoustic Predictions

Abstract

Reduction of noise emissions from helicopters is a long term objective of the helicopter industry in view of extending the market to new civil applications, as well as getting prepared to comply with new and more stringent airport regulations. In this connection the helicopter industry has defined specific technical targets and research objectives. With reference to HeliNOVI two specific technical objectives have been defined: - the definition of a high quality experimental data base on a Mach scaled full helicopter configuration; - the adaptation and validation of reliable prediction tools, with reference to this new database. The present report refers to the second objective and deals with pre-test predictions using the codes available within the HeliNOVI consortium. The aim is • to give an overview of the results obtained during the pre-test computational activities; • to detect possible errors in the pre-test calculations; • to provide whenever possible a physical interpretation of the predictions; • to sketch some guidance for the following tasks. The pre-test prediction activity has been conceived in order to have an evaluation of the capabilities of the methodologies available within the consortium in predicting both the flow as well as the acoustic characteristics of a full helicopter configuration in different flight conditions. Furthermore, through code-to-code and code-to-measurements comparisons points for possible improvements can be identified in view of the subsequent prediction activities within HeliNOVI.