Final Report Summary - CARD (Contribution to Analysis of Rotor Hub Drag Reduction)
Executive Summary:
There is increasing concern about the adverse environmental effects of engine emissions which has resulted in the need to identify methods to reduce the fuel burn of helicopters. Significant work has been undertaken and improvements in aerodynamic performance have been gained by using both computational and experimental techniques. It is recognised that a major source of helicopter drag, about 30% of the total, is from the rotor hub. This research programme was undertaken to investigate this subject and identify potential techniques to achieve reductions in hub drag. A wind tunnel test programme was carried out to provide a large, high-quality experimental data set. A 5 blade, scaled helicopter model was designed and manufactured. The model was designed to enable the effect of model geometry to be examined by using a range of different rotor caps, hub fairings and blade sleeve fairings. The overall model aerodynamic loads were measured and the loads generated by the rotor hub and rotor cap were independently obtained using internal load cell balances. Also a 3D Particle Image Velocimetry system was employed to acquire flow field data in regions of interest around the model. A range of representative flight conditions were simulated and this acquired data was then processed to allow the significant features of the helicopters model’s aerodynamic characteristics to be obtained. This would expose the salient sources of rotor hub drag and so identify techniques that may be employed to reduce the magnitude of this force. The data would also be available for the development and validation of CFD codes.
Project Context and Objectives:
This research programme was undertaken to investigate the potential sources of drag associated with the rotor hub of a known helicopter geometry. Initial work had been undertaken by the CfP leader using Computational Fluid Dynamics (CFD) to examine the flow field and identify potential geometries of fairings and cap shapes which will create drag reductions. Following completion of this section of the work, it was necessary then to validate the CFD results using a well planned wind tunnel test programme. This would include the acquisition of aerodynamic forces generated by the helicopter model together with a thorough examination of the surrounding flow field using 3D Particle Image Velocimetry (PIV). The size of the model needed to be as large as possible in order to maximise the magnitude of the generated loads and also enable easier identification of flow field characteristics when using the PIV system.
According to the CfP leader this is the first time that a thorough research programme using both computational and experimental techniques has been undertaken to investigate this subject. The wind tunnel tests would be planned to maximise the amount of relevant data acquired and allow a full understanding of the problem to be obtained. A complicated model was produced which allowed the identification of the loads generated by different sections of the model. Several load cells were installed in the model to achieve this and allowed identification of the loads generated by each of the following; overall model, rotor hub and rotor cap. The results of the work would be valuable in terms of the drag and emission reduction of the rotor hub, beanie cap and blade sleeve fairings. The techniques that would be developed during this programme of work would be available for use in future research activities.
The work plan of the CARD project was divided into four main work packages namely:-
- WP1 is dedicated to the design and manufacture of the 5-bladed helicopter model.
- WP2 covers the preparatory work to be undertaken prior to the wind tunnel tests at VZLU including suitable model control, data acquisition and PIV seeding techniques.
- WP3 is to undertake the test programme in the VZLU wind tunnel and acquire extensive aerodynamic loads and flow field data.
- WP4 is to carry out the management of the work programme.
Project Results:
The model was designed to allow the measurement of the overall model aerodynamic loads together with the loads of specific regions of the model. Suitable load cell balances were identified to allow the acquisition of data for 6-components (3 forces, 3 moments) with high accuracy, resolution and repeatability
The model scale was as large as possible, within wind tunnel constraints, in order to maximise the aerodynamic loads generated, maximise Reynolds number and allow improved examination of detail flow field features when using the PIV systems. The blades were truncated at 1/3rd radius in order to maximise model size.
An incidence gauge and 3 axis accelerometer was installed in the model to help identify blade position and allow acquisition of test data when the rotor blades were at selected azimuthal positions.
Three rotor caps, two hub fairings and three alternative blade sleeve fairings were produced to enable comparisons of their associated drag characteristics. The geometry of the model, e.g. rotor blade and fuselage, was provided by the CfP leader at commencement of the project.
The model was mounted onto the existing wind tunnel model support sting via a 6-component load cell; which permitted measurement of normal force, axial force and side force, and pitching moment, yawing moment and rolling moment for the complete model assembly.
The model structure comprised composite external panels mounted onto a rigid model framework, all attached to an adaptor on the live end of the main model load cell. The air-wetted surfaces of the composite panels were fully-representative of the aircraft external geometry over the top half of the model. The profile on the lower half of the model was an approximation of the aircraft external lines, to facilitate manufacture.
The rigid model framework provided the support for the rotor hub and rotor drive mechanisms, which were mounted to the main support frame via a second 6-component load cell for measurement of forces and moments acting on the rotor hub assembly.
The 5-bladed rotor and hub arrangement was driven by an electric motor and gearbox via a toothed belt. The rotor head enabled variation in pitch to be effected via a manually-indexed mechanism which provided discrete pitch settings. An encoder was connected to the rotor drive system to measure rotor rpm.
A third 6-component load cell/balance was installed between the cap and its attachment point to rotor head to provide measurements of the forces and moments acting upon the cap. A slip ring assembly was installed between the rotating cap and the stationary support to permit balance signals to be transmitted to the data loggers.
A complete digital mock-up of the CAD model was provided to the customer in Catia v5 format.
The wind tunnel test programme was undertaken at VZLU. The wind tunnel has a 3m diameter open working section facility with a maximum velocity of 70 m/sec. The open working section would provide many advantages, especially in providing uninterrupted optical access for the PIV systems.
The test programme, including test conditions and positions for the measurement of flow field data using the PIV systems was provided by the CfP leader.
It was anticipated that the immediate impact would be the availability of a high-quality experimental data set which can be used to obtain a thorough understanding of the complex flow field around the helicopter rotor. The data can also be used in the development and validation of the CFD codes used to predict flows in this area.
The wind tunnel model and measurement techniques developed during this programme of work would be available for use in future experimental investigations.
This information will be utilised in the design of future helicopters in order to reduce their overall drag with the associated reduction in fuel burn and hence engine emission. This will assist in reducing the problem of environmental impact and provide the community with a better living environment. The improved aerodynamic performance of the helicopter will also result in a reduction of noise generation which will produce significant benefits to the local environment.
WP1 – Design and Manufacture – Lead Participant ARA
The original timeline for Design of the helicopter model was due for completion by the end of Month 12 from project commencement, and Manufacture intended to start from Month 13. This equates to the end of Oct 2011 and the beginning of Nov 2011 respectively
As described in the First Periodic Report, a Preliminary Design Review (PDR) had been held in early March 2012 at which time the CAD model was around 50% complete and Manufacture had commenced
Despite this short delay, progress was recovered during this Second Period such that the Model was delivered to the Wind Tunnel facility at VZLU during May 2013 as per the original schedule and a preliminary Model Stress Report was also issued
However relatively early in the test campaign during June 2013, a significant failure occurred of the Model which entailed aborting the test and ultimately to a request to extend the project duration to the date now relevant to the Second Periodic Report ( 1 May 2012 – 31 Oct 2014 )
This extension was to allow for the appropriate analysis and rectification of the Model at ARA to permit a further Test Campaign within the VZLU Wind Tunnel facility, as requested by the Topic Manager
The Work Package was successfully achieved in line with the agreed re-schedule
WP2 – Test Preparation – Lead Participant UoG
As originally scheduled, work initially concentrated between UoG and ARA, on the design and manufacturing methodologies to be used later during UoG’s production of the helicopter fuselage skins and also the 5 truncated blades of the rotor
This work was completed on time and the respective hardware was supplied to ARA to enable assembly and initial trialling of the model
At this time the Data Acquisition System and Model Control System supplied by UoG was also verified, and following Model Approval by the Topic Manager in early April 2013, these units together with the fully assembled Model were shipped to the Wind Tunnel facility at VZLU in preparation for initial testing to commence in June 2013
However as stated above, relatively early in the test campaign during June 2013, a significant failure occurred of the Model which entailed aborting the test and ultimately to a request to extend the project duration
Following further analysis, minor design changes and subsequent rectification work including incorporation of new replacement Load Cells for the Rotor and Beanie, the Model was returned to VZLU in August 2014
ARA and UoG provided further technical support with regard to installation and preparation within the VZLU Test Facility and all aspects of the UoG Deliverables for this Work Package were available in accordance with the extended and revised timeframe
WP3 – Wind Tunnel Test – Lead Participant VZLU
Following the rectification work at ARA, the Model was returned to VZLU in August 2014
During the interim, Airbus Helicopters had provided to all parties a new and revised Test Matrix schedule
In order to minimise the risks of another failure of the rotor head, a maximum incoming-flow velocity of 45m/s was designated. Compared to the former test matrix, this represents a reduction by 15 m/s
The rotor-head’s angular velocity had also been reduced accordingly, in order to maintain the advance ratio as constant. Consequently, the updated maximal angular velocity was 748 rpm. Those values correspond to a reduction of the Reynolds Number (Full scale over Wind-Tunnel scale) by a factor 7, which still remains satisfactory. As loads are a function of the square of the velocities, those revised values should reduce the maximum loads by a factor 2
In addition, the progress of configuration runs shown below was designed in order also to limit the impact of a failure of the rotor head on the amount of collected data
— Isolated fuselages were investigated first;
— Then, different configurations were blown with a non-rotating rotor head;
— Investigated then were the different complete configurations in “Approach” conditions, for which the incoming velocity and rpm were 20 m/s & 664 rpm respectively;
— Then a “wool-tufts” session was proposed, in order to collect data related to flow separations over the cowlings in the “Approach” conditions, while limiting the number of instrumentation of the model with tufts;
— Finally, the “Cruise” conditions were investigated, by considering first a variation of the sleeves’ design, then a variation of the hub caps’ design. This was the most critical point of the Test Matrix, as the maximum velocity and rpm were required;
The Test Matrix was completed satisfactorily, although there was some drift reported from the new Load Cells
Final technical reports are available
The Model was returned to ARA for storage during October 2014
WP4 – Project Management – Lead Participant ARA
Technical management and financial administration has been maintained by ARA throughout the duration of this 2nd Periodic Report, but during the whole project there have been several enforced changes due to personnel leaving their employment.
Mr David Hurst followed by Mr Tilman Hetsch were ARA Project Co-ordinators during this Period, and Mr Ian Potter was our Financial focal
However from March 2012, Mr Rob Daly has taken over the Financial and Project Co-ordinator roles, with my assistance for the latter functionality
A personnel change also occurred during the same timeframe at UoG, where Mr Richard Green replaced Mr Roddy Galbraith as the main contact
Mr David Zacho remained as the main focal at VZLU
Although the Model was supplied to the test facility at VZLU in accordance with the agreed schedule at the time, during the early stages of testing there was a component failure which meant that the testing had to be aborted
During subsequent stripdown and analysis it was clear that the 4 screws mounting the main rotor head assembly to the rotor Load Cell had broken
Initial thoughts were that the dowels may have worked their way out under vibration, contacting the beanie mount and transferring rotor torque to the screws, which then failed in shear.
Examination of the assembly and dimensions of dowel, gap and dowel hole depth show that the dowels could not have fallen out completely and must have continued to transfer rotor torque.
Two indents on opposite sides of the underside of the beanie mount show that the top of the rotor load cell has been contacting the underside of the beanie mount where there should have been a 2mm clearance.
The positions of the indents suggest that the rotor was rocking about the load cell dowels. For the load cell/beanie mount contact to occur, the rotor attachment screws must have broken.
Without screws, all blade lift forces would have been transferred from the rotor balance to the beanie balance, which only has 1/5th of the load capacity in the lift direction (Fz)
It is possible that the rocking action of the rotor after the countersunk screws had broken caused the dowels to ‘walk’ out until they contacted the beanie mount.
In hindsight, countersunk screws were not a good choice for attaching the rotor head to the rotor load cell.
Countersunk head screws run the risk of introducing an eccentric load to the screw head, producing a bending moment under the screw head. This is made worse by torque tightening the screws
It was agreed that the countersunk screws should be replaced by cap heads and the countersinks machined into counter bores removing minimal material.
Also, from test reports it seemed highly likely that one or both of the load cells had been damaged. It was agreed that new replacement Load Cells would be purchased for both the Rotor and the Beanie
• The design and manufacture of a 1:4 helicopter scale model was satisfactorily completed, which incorporated customer supplied fuselage and truncated blade geometry (based on the Dauphin helicopter).
• Customer defined configuration variants were also manufactured to enable comparative assessments of their respective impacts on rotor hub drag and hence fuel utilisation, exhaust and also potentially noise emissions.
• A successful wind tunnel test campaign was conducted, which indicated certain trends when comparing the configuration variants
• PIV assessments were also accomplished to provide various flow field data, and the model would be available for further test evaluation and CFD correlation work in the future
Potential Impact:
All intellectual property rights generated under the CARD project are owned by the relevant Partners, who could particularly address the exploitation of the results and patenting issues.
Detailed results from this programme, highlighting comparative performance of various design configuration variants, are owned by Airbus Helicopters and dissemination will be at their discretion.
Partners who do wish to publish results should firstly request permission from the CfP Topic Manager and the CARD Clean Sky Work Package Manager who is responsible for the monitoring of this project.
There is increasing concern about the adverse environmental effects of engine emissions which has resulted in the need to identify methods to reduce the fuel burn of helicopters. Significant work has been undertaken and improvements in aerodynamic performance have been gained by using both computational and experimental techniques. It is recognised that a major source of helicopter drag, about 30% of the total, is from the rotor hub. This research programme was undertaken to investigate this subject and identify potential techniques to achieve reductions in hub drag. A wind tunnel test programme was carried out to provide a large, high-quality experimental data set. A 5 blade, scaled helicopter model was designed and manufactured. The model was designed to enable the effect of model geometry to be examined by using a range of different rotor caps, hub fairings and blade sleeve fairings. The overall model aerodynamic loads were measured and the loads generated by the rotor hub and rotor cap were independently obtained using internal load cell balances. Also a 3D Particle Image Velocimetry system was employed to acquire flow field data in regions of interest around the model. A range of representative flight conditions were simulated and this acquired data was then processed to allow the significant features of the helicopters model’s aerodynamic characteristics to be obtained. This would expose the salient sources of rotor hub drag and so identify techniques that may be employed to reduce the magnitude of this force. The data would also be available for the development and validation of CFD codes.
Project Context and Objectives:
This research programme was undertaken to investigate the potential sources of drag associated with the rotor hub of a known helicopter geometry. Initial work had been undertaken by the CfP leader using Computational Fluid Dynamics (CFD) to examine the flow field and identify potential geometries of fairings and cap shapes which will create drag reductions. Following completion of this section of the work, it was necessary then to validate the CFD results using a well planned wind tunnel test programme. This would include the acquisition of aerodynamic forces generated by the helicopter model together with a thorough examination of the surrounding flow field using 3D Particle Image Velocimetry (PIV). The size of the model needed to be as large as possible in order to maximise the magnitude of the generated loads and also enable easier identification of flow field characteristics when using the PIV system.
According to the CfP leader this is the first time that a thorough research programme using both computational and experimental techniques has been undertaken to investigate this subject. The wind tunnel tests would be planned to maximise the amount of relevant data acquired and allow a full understanding of the problem to be obtained. A complicated model was produced which allowed the identification of the loads generated by different sections of the model. Several load cells were installed in the model to achieve this and allowed identification of the loads generated by each of the following; overall model, rotor hub and rotor cap. The results of the work would be valuable in terms of the drag and emission reduction of the rotor hub, beanie cap and blade sleeve fairings. The techniques that would be developed during this programme of work would be available for use in future research activities.
The work plan of the CARD project was divided into four main work packages namely:-
- WP1 is dedicated to the design and manufacture of the 5-bladed helicopter model.
- WP2 covers the preparatory work to be undertaken prior to the wind tunnel tests at VZLU including suitable model control, data acquisition and PIV seeding techniques.
- WP3 is to undertake the test programme in the VZLU wind tunnel and acquire extensive aerodynamic loads and flow field data.
- WP4 is to carry out the management of the work programme.
Project Results:
The model was designed to allow the measurement of the overall model aerodynamic loads together with the loads of specific regions of the model. Suitable load cell balances were identified to allow the acquisition of data for 6-components (3 forces, 3 moments) with high accuracy, resolution and repeatability
The model scale was as large as possible, within wind tunnel constraints, in order to maximise the aerodynamic loads generated, maximise Reynolds number and allow improved examination of detail flow field features when using the PIV systems. The blades were truncated at 1/3rd radius in order to maximise model size.
An incidence gauge and 3 axis accelerometer was installed in the model to help identify blade position and allow acquisition of test data when the rotor blades were at selected azimuthal positions.
Three rotor caps, two hub fairings and three alternative blade sleeve fairings were produced to enable comparisons of their associated drag characteristics. The geometry of the model, e.g. rotor blade and fuselage, was provided by the CfP leader at commencement of the project.
The model was mounted onto the existing wind tunnel model support sting via a 6-component load cell; which permitted measurement of normal force, axial force and side force, and pitching moment, yawing moment and rolling moment for the complete model assembly.
The model structure comprised composite external panels mounted onto a rigid model framework, all attached to an adaptor on the live end of the main model load cell. The air-wetted surfaces of the composite panels were fully-representative of the aircraft external geometry over the top half of the model. The profile on the lower half of the model was an approximation of the aircraft external lines, to facilitate manufacture.
The rigid model framework provided the support for the rotor hub and rotor drive mechanisms, which were mounted to the main support frame via a second 6-component load cell for measurement of forces and moments acting on the rotor hub assembly.
The 5-bladed rotor and hub arrangement was driven by an electric motor and gearbox via a toothed belt. The rotor head enabled variation in pitch to be effected via a manually-indexed mechanism which provided discrete pitch settings. An encoder was connected to the rotor drive system to measure rotor rpm.
A third 6-component load cell/balance was installed between the cap and its attachment point to rotor head to provide measurements of the forces and moments acting upon the cap. A slip ring assembly was installed between the rotating cap and the stationary support to permit balance signals to be transmitted to the data loggers.
A complete digital mock-up of the CAD model was provided to the customer in Catia v5 format.
The wind tunnel test programme was undertaken at VZLU. The wind tunnel has a 3m diameter open working section facility with a maximum velocity of 70 m/sec. The open working section would provide many advantages, especially in providing uninterrupted optical access for the PIV systems.
The test programme, including test conditions and positions for the measurement of flow field data using the PIV systems was provided by the CfP leader.
It was anticipated that the immediate impact would be the availability of a high-quality experimental data set which can be used to obtain a thorough understanding of the complex flow field around the helicopter rotor. The data can also be used in the development and validation of the CFD codes used to predict flows in this area.
The wind tunnel model and measurement techniques developed during this programme of work would be available for use in future experimental investigations.
This information will be utilised in the design of future helicopters in order to reduce their overall drag with the associated reduction in fuel burn and hence engine emission. This will assist in reducing the problem of environmental impact and provide the community with a better living environment. The improved aerodynamic performance of the helicopter will also result in a reduction of noise generation which will produce significant benefits to the local environment.
WP1 – Design and Manufacture – Lead Participant ARA
The original timeline for Design of the helicopter model was due for completion by the end of Month 12 from project commencement, and Manufacture intended to start from Month 13. This equates to the end of Oct 2011 and the beginning of Nov 2011 respectively
As described in the First Periodic Report, a Preliminary Design Review (PDR) had been held in early March 2012 at which time the CAD model was around 50% complete and Manufacture had commenced
Despite this short delay, progress was recovered during this Second Period such that the Model was delivered to the Wind Tunnel facility at VZLU during May 2013 as per the original schedule and a preliminary Model Stress Report was also issued
However relatively early in the test campaign during June 2013, a significant failure occurred of the Model which entailed aborting the test and ultimately to a request to extend the project duration to the date now relevant to the Second Periodic Report ( 1 May 2012 – 31 Oct 2014 )
This extension was to allow for the appropriate analysis and rectification of the Model at ARA to permit a further Test Campaign within the VZLU Wind Tunnel facility, as requested by the Topic Manager
The Work Package was successfully achieved in line with the agreed re-schedule
WP2 – Test Preparation – Lead Participant UoG
As originally scheduled, work initially concentrated between UoG and ARA, on the design and manufacturing methodologies to be used later during UoG’s production of the helicopter fuselage skins and also the 5 truncated blades of the rotor
This work was completed on time and the respective hardware was supplied to ARA to enable assembly and initial trialling of the model
At this time the Data Acquisition System and Model Control System supplied by UoG was also verified, and following Model Approval by the Topic Manager in early April 2013, these units together with the fully assembled Model were shipped to the Wind Tunnel facility at VZLU in preparation for initial testing to commence in June 2013
However as stated above, relatively early in the test campaign during June 2013, a significant failure occurred of the Model which entailed aborting the test and ultimately to a request to extend the project duration
Following further analysis, minor design changes and subsequent rectification work including incorporation of new replacement Load Cells for the Rotor and Beanie, the Model was returned to VZLU in August 2014
ARA and UoG provided further technical support with regard to installation and preparation within the VZLU Test Facility and all aspects of the UoG Deliverables for this Work Package were available in accordance with the extended and revised timeframe
WP3 – Wind Tunnel Test – Lead Participant VZLU
Following the rectification work at ARA, the Model was returned to VZLU in August 2014
During the interim, Airbus Helicopters had provided to all parties a new and revised Test Matrix schedule
In order to minimise the risks of another failure of the rotor head, a maximum incoming-flow velocity of 45m/s was designated. Compared to the former test matrix, this represents a reduction by 15 m/s
The rotor-head’s angular velocity had also been reduced accordingly, in order to maintain the advance ratio as constant. Consequently, the updated maximal angular velocity was 748 rpm. Those values correspond to a reduction of the Reynolds Number (Full scale over Wind-Tunnel scale) by a factor 7, which still remains satisfactory. As loads are a function of the square of the velocities, those revised values should reduce the maximum loads by a factor 2
In addition, the progress of configuration runs shown below was designed in order also to limit the impact of a failure of the rotor head on the amount of collected data
— Isolated fuselages were investigated first;
— Then, different configurations were blown with a non-rotating rotor head;
— Investigated then were the different complete configurations in “Approach” conditions, for which the incoming velocity and rpm were 20 m/s & 664 rpm respectively;
— Then a “wool-tufts” session was proposed, in order to collect data related to flow separations over the cowlings in the “Approach” conditions, while limiting the number of instrumentation of the model with tufts;
— Finally, the “Cruise” conditions were investigated, by considering first a variation of the sleeves’ design, then a variation of the hub caps’ design. This was the most critical point of the Test Matrix, as the maximum velocity and rpm were required;
The Test Matrix was completed satisfactorily, although there was some drift reported from the new Load Cells
Final technical reports are available
The Model was returned to ARA for storage during October 2014
WP4 – Project Management – Lead Participant ARA
Technical management and financial administration has been maintained by ARA throughout the duration of this 2nd Periodic Report, but during the whole project there have been several enforced changes due to personnel leaving their employment.
Mr David Hurst followed by Mr Tilman Hetsch were ARA Project Co-ordinators during this Period, and Mr Ian Potter was our Financial focal
However from March 2012, Mr Rob Daly has taken over the Financial and Project Co-ordinator roles, with my assistance for the latter functionality
A personnel change also occurred during the same timeframe at UoG, where Mr Richard Green replaced Mr Roddy Galbraith as the main contact
Mr David Zacho remained as the main focal at VZLU
Although the Model was supplied to the test facility at VZLU in accordance with the agreed schedule at the time, during the early stages of testing there was a component failure which meant that the testing had to be aborted
During subsequent stripdown and analysis it was clear that the 4 screws mounting the main rotor head assembly to the rotor Load Cell had broken
Initial thoughts were that the dowels may have worked their way out under vibration, contacting the beanie mount and transferring rotor torque to the screws, which then failed in shear.
Examination of the assembly and dimensions of dowel, gap and dowel hole depth show that the dowels could not have fallen out completely and must have continued to transfer rotor torque.
Two indents on opposite sides of the underside of the beanie mount show that the top of the rotor load cell has been contacting the underside of the beanie mount where there should have been a 2mm clearance.
The positions of the indents suggest that the rotor was rocking about the load cell dowels. For the load cell/beanie mount contact to occur, the rotor attachment screws must have broken.
Without screws, all blade lift forces would have been transferred from the rotor balance to the beanie balance, which only has 1/5th of the load capacity in the lift direction (Fz)
It is possible that the rocking action of the rotor after the countersunk screws had broken caused the dowels to ‘walk’ out until they contacted the beanie mount.
In hindsight, countersunk screws were not a good choice for attaching the rotor head to the rotor load cell.
Countersunk head screws run the risk of introducing an eccentric load to the screw head, producing a bending moment under the screw head. This is made worse by torque tightening the screws
It was agreed that the countersunk screws should be replaced by cap heads and the countersinks machined into counter bores removing minimal material.
Also, from test reports it seemed highly likely that one or both of the load cells had been damaged. It was agreed that new replacement Load Cells would be purchased for both the Rotor and the Beanie
• The design and manufacture of a 1:4 helicopter scale model was satisfactorily completed, which incorporated customer supplied fuselage and truncated blade geometry (based on the Dauphin helicopter).
• Customer defined configuration variants were also manufactured to enable comparative assessments of their respective impacts on rotor hub drag and hence fuel utilisation, exhaust and also potentially noise emissions.
• A successful wind tunnel test campaign was conducted, which indicated certain trends when comparing the configuration variants
• PIV assessments were also accomplished to provide various flow field data, and the model would be available for further test evaluation and CFD correlation work in the future
Potential Impact:
All intellectual property rights generated under the CARD project are owned by the relevant Partners, who could particularly address the exploitation of the results and patenting issues.
Detailed results from this programme, highlighting comparative performance of various design configuration variants, are owned by Airbus Helicopters and dissemination will be at their discretion.
Partners who do wish to publish results should firstly request permission from the CfP Topic Manager and the CARD Clean Sky Work Package Manager who is responsible for the monitoring of this project.