Hazardous Particle Detection via Unmanned Air Vehicles

Optimal Placement of Sensors in Forward Flight

In collaboration with the Boeing Company, under DARPA funding

Goals of the Study

  • To find out if the efficiency with which UAV's can be used to scan the atmosphere for hazardous particles can be enhanced by suitably situating the particle collector.

  • If position is important, then provide a predictive tool for finding the optimal sensor location for particular UAV configurations.

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 Model Problem

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Planes of particles enter the flow upstream of the helicopter at regular intervals. Particles on each incoming plane are equally distributed over a circular region.

 
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2D side view of the particles washing over the helicopter

3D view of particles

Animation of the movement of one disk of particles

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Animations of all particles: red particles are within .015 of viewing plane.

Animations of all particles: red particles are within .015 of viewing plane.

 
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3D animation of particle paths

 

Collection of paths beginning at the same location

Effect of Stokes number on particle paths

Effect of Stokes number on particle paths

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St = 10

St = 10

St = 0 (tracers)                                  

St = 0 (tracers)                                  

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Paths arriving at airframe locations for whom initial separation is greatest: results are similar for two rotor models.

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Conclusions

  • Particle collector placement appears to have a significant effect on the efficiency with which the upstream flow can be examined for hazards.

  • For the particular airframe, rotor model and flow conditions considered here, the tail section of the helicopter offers the best location for particle collection.

  • The versatility and effectiveness of the Vorcat approach in rapidly studying complex flow phenomena is evident. 

  • To the best of our knowledge, this flow scenario has not been tested experimentally.