Installed Performance of Dual vs. Single Stage Ducted Fans at subsonic speeds Sina Golshany 12/09/2018
Dual vs. Single Stage Ducted Fans
Dual-Stage, Contra Rotating Ducted Fan
Single-Stage, Ducted Fan with guide vanes
Single Stage Net Thrust vs. Airspeed & RPM
Air Speed [m/sec]:
Single Stage Net Thrust vs. Airspeed & RPM
Single Stage Net Efficiency vs. Airspeed & RPM
Air Speed [m/sec]:
Single Stage Net Efficiency vs. Airspeed & RPM
Single Stage Fan Torque vs. Airspeed & RPM
Air Speed [m/sec]:
Single Stage Fan Torque vs. Airspeed & RPM
Single Stage Fan Performance Sensitivity 2 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Sensitivity 10 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Sensitivity 18 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Metrics 2 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Metrics 10 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Metrics 18 m/sec airspeed and 6800 RPM
Dual Stage Net Thrust vs. Fore/Aft Fan Speed Airspeed 2 [m/sec]
Aft Fan Speed [rad/sec]
Dual Stage Net Thrust vs. Fore/Aft Fan Speed Airspeed at 2 m/sec
Dual Stage Net Efficiency vs. Fore/Aft Fan Speed Airspeed 2 [m/sec]
Note: Efficiency values above 100% are an artifact of interpolation errors in the fringes of the design exploration space.
Aft Fan Speed [rad/sec]
Dual Stage Net Efficiency vs. Fore/Aft Fan Speed Airspeed 2 [m/sec]
Dual Stage Net Efficiency vs. Fore/Aft Fan Speed Airspeed 18 [m/sec]
Aft Fan Speed [rad/sec]
Dual Stage Net Efficiency vs. Fore/Aft Fan Speed Airspeed 18 [m/sec]
Dual Stage Net Thrust vs. Fore/Aft Fan Speed Airspeed 18 [m/sec]
Aft Fan Speed [rad/sec]
Dual Stage Net Thrust vs. Fore/Aft Fan Speed Airspeed at 18 m/sec
Dual Stage Fan Performance Sensitivity 2 m/sec airspeed and 6000 RPM
Dual Stage Fan Performance Sensitivity 10 m/sec airspeed and 6000 RPM
Dual Stage Fan Performance Sensitivity 18 m/sec airspeed and 6000 RPM
Single Stage Fan Performance Metrics 2 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Metrics 10 m/sec airspeed and 6800 RPM
Single Stage Fan Performance Metrics 18 m/sec airspeed and 6800 RPM
Point Design Performance Comparison • Three comparisons are performed. Optimal RPM, (fore/aft for the dual fan) are computed to identify the highest efficiency point at three design speeds: • 2 m/sec (stationary maneuvering), 30 [lbf] • 10 m/sec (transition to cruise), 30 [lbf] • 15 m/sec (cruise), 30 [lbf]
• A Multi-Objective Genetic Algorithm (MOGA) is used to identify best of 3 candidates out of 3000 initial samples, subject to the following criteria: • 29.75 [lbf]< Net Force < 30.25 [lbf] • Maximize Net Efficiency • Seek Airspeed Equal to the objective (2,10, or 15 m/sec)
Point Design Performance Comparison â&#x20AC;¢ Single Fan Optimal Combinations: Condition:
2 [m/sec]
10 [m/sec]
15 [m/sec]
Forward Fan Speed [rad/sec]
740
780
820
Aft Fan Speed [rad/sec]
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Net Efficiency [%]
87
68
53
Forward Fan Torque [N-m]
6.35
6.40
6.50
Aft Fan Torque [N-m]
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Point Design Performance Comparison â&#x20AC;¢ Dual Fan Optimal Combinations: Condition:
2 [m/sec]
10 [m/sec]
15 [m/sec]
Forward Fan Speed [rad/sec]
629.8
744.7
746.9
Aft Fan Speed [rad/sec]
708.6
534.6
730.1
Net Efficiency [%]
97
65
53
Forward Fan Torque [N-m]
1.10
5.10
2.72
Aft Fan Torque [N-m]
-5.52
-1.699
-4.71