In this paper, a computational fluid dynamics simulation method is developed to study the influence of rotor overlapping azimuth on aerodynamic performance compound coaxial helicopter. The verified by comparing numerical results with wind tunnel experiment data NASA rotor. Two azimuths upper and lower blades are considered, isolated helicopter in hover forward analyzed respectively. State 1 mea...

The aerodynamic interaction between the rotor and fuselage is an important consideration in relation to drag performance prediction of helicopters. In this paper, based on dynamic patched-grid technology coupled with a three-dimensional N–S equation solver, numerical study effects flow field light civil helicopter carried out under forward flight condition. deterioration evolution structure cau...

This paper presents a new mathematical model for a model-scale helicopter. Working from first principles and basic aerodynamics, the equations of motion for full six degree-of-freedom motion are derived. The control inputs considered are the four pilot commands from the radio transmitter: roll, pitch, yaw, and thrust. The model helicopter has a fast time-domain response due to its small size, a...

The benefits of applying multiple alternatives for mock-up and compression of helicopter harmonic motion are analyzed. Multiple mock-up approaches, along with a weighted-average mechanism, are approximated so that quicksand affiliated with only applying alone better alternate for the rotor blade vibration-reduction dilemma are bypassed. A harmonic motion external function matching to a flight c...

SUMMARY This work first describes the development of a real-time flight simulator for an R-50 experimental model helicopter. A mathematical model of the helicopter is developed to represent the dynamics of the real system. This simulation model is used to investigate and analyze the helicopter dynamics in a hovering flight condition. The importance of a control rotor used for stability augmenta...

Title of dissertation: SIMULATION MODELING OF FLIGHT DYNAMICS, CONTROL AND TRAJECTORY OPTIMIZATION OF ROTORCRAFT TOWING SUBMERGED LOADS Ananth Sridharan, Doctor of Philosophy, 2014 Dissertation directed by: Professor Roberto Celi Department of Aerospace Engineering This work presents the mathematical modeling and analysis of helicopters towing submerged loads using long cables for sub-surface o...

A computational study of helicopter vibration and rotor shaft power reduction is conducted using activelycontrolled trailing-edge flaps (ACFs), implemented in both single and dual flap configurations. Simultaneous vibration reduction and performance enhancement is demonstrated under level flight condition at high advance ratios, where dynamic stall effects are significant. Power reduction is ac...

There is currently interest in the design of small electric vertical take-off and landing aircraft to alleviate ground traffic congestion major urban areas. To support progress this area, a conceptual method for single-main-rotor lift-augmented compound helicopters has been developed. The was used investigate feasible space based on varying mission profiles technology assumptions. Within space,...

Stability and control of rotors at high advance ratio are considered. Stability of teetering, articulated, and gimbaled hub types is considered with a simple flapping blade analysis. Rotor control in autorotation for teetering and articulated hub types is examined in more detail for a compound helicopter (rotor and fixed wing) using the comprehensive analysis CAMRAD II. Autorotation is found to...