SmartTab - Active Trim Tab for Rotor Blades
Scaled Model Whirl Test Results
The results of this SBIR Phase II program have clearly demonstrated that active trim tabs can operate on the rotating frame of a helicopter. Midé tested the active trim tab concept at the Model Test Facility of Sikorsky Aircraft Corporation in Stratford CT. The centrifugal loads of a rotor did not adversely affect the operation of the tabs. The deflection of the tabs was sufficient to affect the changes that would be desired in order to bring the main rotor blades into track although additional authority would be beneficial. The next logical step would be to implement a full-scale tab on a full-scale blade and perform additional whirl tests.
Below is an example plot of the RADS blade trackers. The dimensions reflect the relative track of one blade referenced from the average track position of the two blades. The first data point for the 10° collective is low because of additional cooling as a result of being deflected further into the flow, which retarded the heating of the tabs. The data point was collected at the same time after initiating the heater, but the deflection was delayed. Subsequent points however show the track was affected once the tabs heated and deflected.
Figure 7: RADS tracker data at 600 RPM tests showing the effect of the tab deflection, while rotating.
Conclusions
Midé developed an automatic active trim tab solution that will significantly reduce the maintenance effort and cost of the rotor track and balancing (RT&B) process, as well as minimize airframe vibrations. Midé’s trim tab adjustment system may be performed automatically without maintenance. The developments of an active rotor trim tab system will save flight costs, reduce maintenance time and costs, and reduce vibration induced human and airframe fatigue. In short the innovation will allow helicopter’s to spend more time in the air performing missions.
The benefits of the Solid-State Active Trim Tab (SSATT) include:
- Eliminate helicopter downtime for trimming of tabs
- Solid state actuator results in highly robust system
- Reduced scheduled maintenance costs
- Reduced flight/fuel costs associated with determining track and balancing
- Reduce average vibratory loading over lifecycle of helicopter
- Decrease fatigue of aircrew caused by vibrations
- Increased mission availability by minimized downtime
- Enhanced survivability of the rotorcraft
For more information:
Please email Attila Lengyel (Products), or call: 781-306-0609 x225