Optimization of Rotor System for Prescribed Gross Weight and Flight Conditions
1.1
Analysis of dimensional, weight and balance and performance data of worldwide existing helicopters of the similar type.
1.2
Specification of basic data for rotor system optimization, namely:
- rotor disc loading;
- tip speed;
-rotor solidity ratio under no flow separation conditions.
1.3
Analysis of helicopter airfoils. Evaluation of blade airfoil and twist.
1.4
Specification of blade geometric, kinematic, inertia and weight characteristics on the basis of statistical data and corrected for rotor limitations. Assurance of acceptable autorotation performance.
1.5
Optimization of blade geometry.
2
Analysis of Helicopter Basic Performance Characteristics on the Basis of the Modified Mil-Yaroshenko Method of Analysis (prior analysis)
2.1
Construction of power required and available charts for different flight altitudes.
2.2
Evaluation of helicopter reference speeds and flight conditions.
2.3
Evaluation of helicopter steady climb performance in forward flight.
2.4
Evaluation of helicopter range and endurance based on prescribed power plant characteristics.
2.5
Evaluation of helicopter autorotation performance.
3
Specification of Helicopter Performance Requirements Based on Prior Research (elaboration of helicopter design specifications)
3.1
Specification of helicopter weight and balance requirements.
3.2
Specification of helicopter performance requirements.
3.3
Specification of power plant requirements.
4
Analysis of Main Rotor Designs for Rotor Performance Throughoutt Operating Conditions
4.1
Analysis of main rotor performance under vertical drag conditions, namely:
- analysis of rotor drag polar and hovering power required;
- evaluation of rotor efficiency throughout design operating conditions;
- analysis of blade aerodynamic load distribution;
- analysis of rotational speed effect on the main rotor performance under:
- in ground effect conditions;
- vortex ring conditions.
4.2
Analysis of main rotor performance under cross-flow drag conditions, namely:
- rotor drag polar for speed analysis;
- blade flapping motion for flight speed analysis;
- analysis of blade radial and azimuthal aerodynamic loading;
- analysis of rotational speed impact on main rotor performance.
4.3
Evaluation of flapping compensator requirements.
4.4
Prediction of helicopter maximum flight speed in terms of:
- critical region of Reynolds numbers;
- flow separation at retreating blade;
- control loads;
-engine power available.
5
Wind Tunnel Investigation of Helicopter Models in the Wind Tunnel Model Т-4 of the National Aerospace University “Kharkiv Aviation Institute”)
5.1
Design and manufacture of helicopter wind-tunnel models.
5.2
Investigation of wind-tunnel drag polars for longitudinal and lateral control channels.
5.3
Investigation of aerodynamic characteristics of helicopter models with and without horizontal and vertical stabilizers.
5.4
Visual representation of the airflow about the model throughout flight conditions.
5.5
Investigation of the airframe drag resisting measures.
5.6
Investigation of the airframe vertical drag.
6
Analysis of Disturbance Velocity Field and Variation of Kinematic Parameters of the Airflow in the Airframe Vicinity Throughout Flight Conditions
6.1
Discrete vortex analysis of aerodynamic characteristics.
6.2
Downwash velocity field analysis.
6.3
Analysis of the flow kinematic parameters variation.
6.4
Loads analysis of helicopter stabilizers with and without consideration for main rotor effect.
7
Aerodynamic Analysis of Tail Rotors (investigation of main design loading conditions, specification of basic data for strength analysis of the tail boom)
7.1
Analysis of tail rotor power requirements.
7.2
Specification of tail rotor basic geometric and kinematic parameters.
7.3
Evaluation of tail rotor hover and turning performance.
7.4
Evaluation of tail rotor performance under vortex ring conditions.
7.5
Evaluation of tail rotor performance under horizontal flight conditions.
7.6
Evaluation of tail rotor (re)conversion performance.
7.7
Analysis of main rotor – tail rotor interference throughout flight conditions.
8
Analysis of Swash Plate Assembly Geometric and Kinematic Characteristics
8.1
Analysis of main rotor longitudinal and lateral control gain.
8.2
Investigation of control system lead angles.
9
Analysis of Helicopter Longitudinal Trim Throughout Flight Conditions and CG Variations
9.1
Analysis of helicopter longitudinal trim in horizontal flight.
9.2
Analysis of helicopter longitudinal trim in climb.
9.3
Analysis of helicopter longitudinal trim in autorotation.
9.4
Investigation of margins of control.
9.5
Analysis of maximum flight speed corrected for longitudinal trim.
10
Analysis of Helicopter Lateral Trim Throughout Flight Conditions
10.1
Analysis of helicopter lateral trim in horizontal flight.
10.2
Analysis of helicopter lateral trim in autorotation.
10.3
Analysis of helicopter lateral trim under forward slip conditions.
11
Analysis of Helicopter Rate of Climb Performance
11.1
Hover ceiling for gross weight analysis.
11.2
Analysis of vertical rate of climb performance.
11.3
Hover ceiling for temperature analysis.
12
Specification of helicopter performance corrected for trim and operating limitations.
12.1
Analysis of reference speeds and flight conditions.
12.2
Analysis of helicopter rate of climb performance.
12.3
Service ceiling analysis.
12.4
IGE, OGE hover ceiling analysis.
13
Analysis of Helicopter Static Longitudinal and Lateral Stability and Controllability
13.1
Analysis of helicopter static longitudinal stability versus speed and angle of attack.
13.2
Analysis of helicopter longitudinal controllability throughout flight conditions.
13.3
Analysis of helicopter lateral stability and controllability throughout flight conditions.
13.4
Analysis of results.
14
Analysis of Helicopter Design Loading Conditions (specification of basic data for strength analysis)
14.1
Analysis of airworthiness standards.
14.2
Analysis of design loading conditions in flight.
14.3
Analysis of design loading conditions in landing.
15
Analysis of Main Rotor Blade and Hub Loading Conditions (specification of basic data for verification of blade strength analysis)
15.1
Fatigue evaluation of blade spar cross-sectional area. Blade mass and inertia evaluation.
15.2
Analysis of blade aerodynamic, mass and inertia loading in azimuth.
15.3
Analysis of blade loading of the main rotor hub throughout flight conditions.
15.4
Analysis of blade stress-strain state throughout design loading conditions.
16
Analysis of Varying Loads for Tail Rotor Hub and Blades (specification of basic data for verification of tail rotor strength analysis)
16.1
Analysis of tail rotor thrust required throughout design loading conditions.
16.2
Analysis of blade aerodynamic, mass and inertia loading conditions
16.3
Analysis of tail rotor hub loading throughout flight conditions.
17
Analysis of Helicopter Control Loads
17.1
Analysis of main rotor blade hinge-moment characteristic.
17.2
Strength analysis of main units and assemblies of the flight control system.
18
Analysis of Main and Tail Rotor Dynamic Characteristics. Evaluation of Rotor Unstable (Divergence, Flutter) Areas
18.1
Investigation of main and tail rotor dynamics.
18.2
Evaluation of flutter margin.
19
Analysis of Blade Natural Oscillations in the Rotation and Thrust Planes. Construction of Resonance Diagrams
19.1
Construction of main and tail rotor resonance diagrams.
20
Preparation of Documentation for Helicopter Certification
20.1
Elaboration of helicopter design specifications.
20.2
Elaboration of the Certification Basis conforming to
АП-27 Aviation Regulations.
20.3
Elaboration of the Certification Basis Conformity Table.
Notes:
1. All the analyses will be performed in compliance with the АП-27 Aviation Regulations and Airworthiness Standards for Normal Category Rotorcraft of the USSR (1971).
2. Each work stage will be performed in compliance with the technical specification approved by the Customer.
5. At present available are programs for:
- static strength analysis of frame structures;
- finite-element method analysis of blades of composite materials.
6. Developed are procedures for service life testing of main and tail rotor blade sections, hub components and attachment fittings.