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Report

Teaser, summary, work performed and final results

Periodic Reporting for period 2 - PROPCONEL (More electric, advanced hydromechanics propeller control components.)

Teaser

Turboprops in the range of 1,800 to 2,000 shaft horsepower (shp) class are currently controlled by hydromechanical components. The equipment for this class of engines generally allows a maximum of two different propeller speeds, they are mechanically connected for pitch...

Summary

Turboprops in the range of 1,800 to 2,000 shaft horsepower (shp) class are currently controlled by hydromechanical components. The equipment for this class of engines generally allows a maximum of two different propeller speeds, they are mechanically connected for pitch control and the oil pressure is provided by a mechanically driven oil pump.
Jihostroj will be responsible for designing, manufacturing and testing advanced components for propeller control, namely propeller control unit, overspeed governor and oil pump. These components will be tested at Safran Helicopter Engines ground test facility.
- The propeller control unit will be based on hydromechanical control (flyweights and beta valve), but will integrate electric actuation for speed target and pitch target. It will also allow synchronising.
- The overspeed governor will be based on hydromechanical control, with electrical overspeed test and feathering. It will be compatible with the propeller control unit.
- The electrical oil pump will be powered with 28VDC, and commanded with a low power input from the engine and propeller computer.

Jihostroj will also be responsible for delivering a dynamic model for each of the components, allowing Safran Helicopter Engines to design and tune engine control laws. The software used shall be Simulink.
Fuel consumption reduction, lower noise emissions and low operational costs of the aerospace diesel engine propulsion unit and therefore of the aircraft using it are in great accordance with preferences of modern society who is gradually increasing its demand for transport activities.
The principal objectives of the project can be summarised in the following items:
- Development of the new advanced propeller control based on electronic components that will enable introduction of a new generation of turboprop engines to the market. Current competitor´s engines are, despite several modernizations, based on design and technology of 1960-1970´s. New sophisticated engine products can significantly contribute to the competitiveness of European companies.
- Significant increase of time between overhaul (TBO) - by approximately 70% compared to currently available products. Maintenance costs reduction has also a positive impact on the environment, as compensation of the product after its life a new product can be realised only after almost double the time comparing to the original solution. Thus, energy and material sources will be saved and environmental burden connected with production of new product reduced.
- New advanced technical solutions for propeller control unit and overspeed governor can improve overall functionality of the turboprop engine and might contribute to better overall engine efficiency and pilot workload reduction.

Work performed

The first project period was devoted to the Preliminary Design Review (PDR) and Detailed Design Review (DDR) documentation creation. Based on frozen technical specification and existing both-side confirmed architecture, Jihostroj engineers started to work on 3D modelling. 3D models of the major propeller control system technical nodes were developed. 3D design and modelling, Strength analysis and Preliminary test plan were linked to the resulting material, which was submitted to the designers and representatives of Safran Helicopter Engines within the PDR document. All previous steps were summarized in document presented to project partners from Safran Helicopter Engines in form of DDR document. The second period was focused on the production preparation, manufacture, asembly and verification the expected resultes by JSV internal tests of PCU and OSG. The FMP went in very shrtened approach through all development phases up to 80% finished work package of parts manufacture.

Final results

The results of both periods materialize the goals set at the beginning.
Propeller blade speed, meeting the specifications of AA 146419, which has so far only been verified by internal JSV tests, combined with more electric ability to control, provides a prerequisite for more efficient instrument intervention than has previously been the case with manual control of turboprop engines.

Synchrophasing ability, meeting quite narrow requirements of AA146419, which is enabled again only by more electrical control, contributes to noise reduction objective.

Significant weight reduction is in aviation always considered a contribution to engine fuel consumption. Compared to current technology, savings of up to 50% are achieved in this characteristics.

Website & more info

More info: http://www.jihostroj.com/en/aerospace/research-projects/propconel.html.