Fig. 1. Small size tactical UAV for reconnaissance
Fig. 2. Wankel rotary engine(38 hp @ 7800 rpm)
Fig. 3. Blade shape along the radial position including designed propeller shape
Fig. 4. Performance curves for the designed propeller
Fig. 5. Comparison of running thrust along the blade span for 1/7 scale Uh-1H rotor blade[10]
Fig. 6. Comparison of noise signal for UH-1H rotor
Fig. 7. Wake geometry for Case 3
Fig. 8. Timewise noise signals at disc plane(1.5 times propeller diameter apart from disc center)
Fig. 9. Noise spectrum for the timewise noise signals
Fig. 10. Chart of sound attenuation in distance
Fig. 11. Typical cases of sound pressure level[15]
Fig. 12. Directivity patterns(solid line: loading noise, dashed line: thickness noise, dotted line: propeller disc plane)
Table 1. Specifications for two tactical UAVs
Table 2. Design parameters for UAV propeller
Table 3. Operating conditions for UAV propeller
Table 4. Overall sound pressure level [dBA]
참고문헌
- H. R. Gwon, K. L. Hwang, and S. R. Park, "Noise Characteristics of the Tactical Unmanned Aerial Vehicle Propeller," KSAS 2016 Fall Conference, pp. 683-684, 2016.
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- Army Technology Shadow 200 RQ-7 Tactical Unmanned Aircraft System (2018) https://www.armytechnology.com/projects/shadow200uav/(accessed August 18, 2018).
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- Guidance of Health and Safety Executive (2018), http://www.hse.gov.uk/noise/advice.htm(accessed August 18, 2018).