Improvement of dynamic response prediction of helicopters

Abstract

Purpose

This paper aims to focus on mathematical model development issues, necessary for a better prediction of dynamic responses of articulated rotor helicopters.

Design/methodology/approach

The methodology is laid out based on model development for an articulated main rotor, using the theories of aeroelastisity, finite element and state‐space represented indicial‐based unsteady aerodynamics. The model is represented by a set of nonlinear partial differential equations for the main rotor within a state‐space representation for all other parts of helicopter dynamics. The coupled rotor and fuselage formulation enforces the use of numerical solution techniques for trim and linearization calculations. The mathematical model validation is carried out by comparing model responses against flight test data for a known configuration.

Findings

Improvements in dynamic prediction of both on‐axis and cross‐coupled responses of helicopter to pilot inputs are observed.

Research limitations/implications

Further work is required for investigation of the unsteady aerodynamics, a state‐space representation, within various compatible dynamic inflow models to describe the helicopter response characteristics.

Practical implications

The results of this work support ongoing research on the development of highly accurate helicopter flight dynamic mathematical models. These models are used as engineering tools both for designing new aerial products such as modernized agile helicopters and optimization of the old version products at minimum time and expense.

Originality/value

Provides further information on the mathematical model development problems associated with advanced helicopter flight dynamics research.

Citation

Shahmiri, F. and Saghafi, F. (2007), "Improvement of dynamic response prediction of helicopters", Aircraft Engineering and Aerospace Technology, Vol. 79 No. 6, pp. 579-592. https://doi.org/10.1108/00022660710829773