“…Symmetric profiles as the NACA0012 are commonly used for rotors, while asymmetric profiles are more commonly used for propellers. Experimental measurements were provided by Ghoddoussi ( 23 ) and his small-scale two blade COMP propeller based on the E387 was picked up for this study. The variations of the thrust and power coefficients with the TSR are given in Fig.…”
Section: 0 Results and Analysismentioning
confidence: 99%
“…10, where for the model, the c l & c d variations were based on Re C =10 5 . For consistency, the experimental propeller results were re-adjusted for the definitions of the thrust and power coefficients, and tip speed ratio as commonly used for rotor aerodynamics and that are used in this study.Figure 10The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile ( 23 ) and the redesigned A7 profile.…”
Section: 0 Results and Analysismentioning
confidence: 99%
“…The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile ( 23 ) and the redesigned A7 profile.…”
Section: 0 Results and Analysismentioning
confidence: 99%
“…This study concentrated on the aerodynamics of the proprotor, but as noted earlier Table 1: Normalized axial velocity u/(U C T ) distribution as induced by an actuator disk of blade constant circulation [15]. Figures 10: The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile [23] and the redesigned A7 profile.…”
Section: Discussionmentioning
confidence: 99%
“…The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile[23] and the redesigned A7 profile. The lift and drag coefficients variations with the angle of attack that are plotted for theprofiles (a) NACA0012 and the CIRCLE-redesigned QM13F of Re D =1.35 10 5 [2] and (b) E387 and the CIRCLE-redesigned A7 of Re D =2 105 [3].…”
Low Reynolds number blade profiles of ReC=105–2×105 as based on the chord length and used for small unnamed air vehicles, and near space applications are investigated for single and counter-rotating (co-axial) proprotors, i.e. acting as rotors or propellers. Such profiles are prone for early stall, significantly reducing their maximum lift to drag ratio. Two profiles previously designed by our continuous surface curvature design approach named as CIRCLE are investigated in order to improve the performance of the proprotors. The profiles are redesigns of the common symmetric NACA0012 and asymmetric E387 profiles. Using general arguments based on composite efficiency and rotor’s lift to drag ratio, the performance envelope is noticeably increased when using the redesigned profiles for high angles of attack due to stall delay.A new approach is derived to account for the distance between the rotors of a co-axial proprotor. It is coupled with a blade element method and is verified against experimental results. Single and co-axial CIRCLE-based proprotors are investigated against the corresponding non-CIRCLE-based proprotors at hover and axial translation. Noticeable improvements are observed in thrust increase and power reduction at high angles of attack of the blade’s profiles, particularly for the co-axial configuration. Plots of thrust, torque, power, composite efficiency and aerodynamic efficiency distributions are given and analysed.
“…Symmetric profiles as the NACA0012 are commonly used for rotors, while asymmetric profiles are more commonly used for propellers. Experimental measurements were provided by Ghoddoussi ( 23 ) and his small-scale two blade COMP propeller based on the E387 was picked up for this study. The variations of the thrust and power coefficients with the TSR are given in Fig.…”
Section: 0 Results and Analysismentioning
confidence: 99%
“…10, where for the model, the c l & c d variations were based on Re C =10 5 . For consistency, the experimental propeller results were re-adjusted for the definitions of the thrust and power coefficients, and tip speed ratio as commonly used for rotor aerodynamics and that are used in this study.Figure 10The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile ( 23 ) and the redesigned A7 profile.…”
Section: 0 Results and Analysismentioning
confidence: 99%
“…The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile ( 23 ) and the redesigned A7 profile.…”
Section: 0 Results and Analysismentioning
confidence: 99%
“…This study concentrated on the aerodynamics of the proprotor, but as noted earlier Table 1: Normalized axial velocity u/(U C T ) distribution as induced by an actuator disk of blade constant circulation [15]. Figures 10: The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile [23] and the redesigned A7 profile.…”
Section: Discussionmentioning
confidence: 99%
“…The variations of the (a) thrust and (b) power coefficients for the two-blade twisted COMP propeller having the E387 profile[23] and the redesigned A7 profile. The lift and drag coefficients variations with the angle of attack that are plotted for theprofiles (a) NACA0012 and the CIRCLE-redesigned QM13F of Re D =1.35 10 5 [2] and (b) E387 and the CIRCLE-redesigned A7 of Re D =2 105 [3].…”
Low Reynolds number blade profiles of ReC=105–2×105 as based on the chord length and used for small unnamed air vehicles, and near space applications are investigated for single and counter-rotating (co-axial) proprotors, i.e. acting as rotors or propellers. Such profiles are prone for early stall, significantly reducing their maximum lift to drag ratio. Two profiles previously designed by our continuous surface curvature design approach named as CIRCLE are investigated in order to improve the performance of the proprotors. The profiles are redesigns of the common symmetric NACA0012 and asymmetric E387 profiles. Using general arguments based on composite efficiency and rotor’s lift to drag ratio, the performance envelope is noticeably increased when using the redesigned profiles for high angles of attack due to stall delay.A new approach is derived to account for the distance between the rotors of a co-axial proprotor. It is coupled with a blade element method and is verified against experimental results. Single and co-axial CIRCLE-based proprotors are investigated against the corresponding non-CIRCLE-based proprotors at hover and axial translation. Noticeable improvements are observed in thrust increase and power reduction at high angles of attack of the blade’s profiles, particularly for the co-axial configuration. Plots of thrust, torque, power, composite efficiency and aerodynamic efficiency distributions are given and analysed.
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