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 4 replaced http://aviation.stackexchange.com/ with https://aviation.stackexchange.com/ edited Apr 13 '17 at 12:59 Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficientExtending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellersOn propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. 3 added 4 characters in body edited Apr 11 '15 at 16:54 Peter Kämpf 174k1515 gold badges441441 silver badges707707 bronze badges Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quitequite a bit has something to sell to you, but I digress. Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. 2 edited body edited Apr 11 '15 at 12:24 Peter Kämpf 174k1515 gold badges441441 silver badges707707 bronze badges Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be affectedinvolved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be affected, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. Winglets on wings help because they increase the volume of air on which the wing can act. Extending the wing span would be much more efficient, but when span is restricted or the maximum wing bending moment is limited, winglets bring a small improvement in efficiency at high lift coefficients. On propellers, however, the winglets would run through air which is already affected by the tips of the propeller. No additional air will be involved, so no efficiency increase will be possible. Please note that propulsive efficiency is increased by accelerating more air by a smaller amount. The formula for the propulsive efficiency $$\eta_p$$ of an air breathing engine is $$\eta_p = \frac{v_{\infty}}{v_{\infty} + \frac{\Delta v}{2}}$$ where $$v_{\infty}$$ is the speed of the inflowing air and $$\Delta v$$ the speed increase of the air affected by the propeller disc. A smaller $$\Delta v$$ acting on a higher mass flow makes the engine more efficient. This effect is most pronounced when $$v_{\infty}$$ is low. The prop tip winglets would operate in a region of high dynamic pressure and generate more friction drag without contributing to the prop's efficiency. By the way: Whoever tells you that winglets reduce induced drag quite a bit has something to sell to you, but I digress. 1 answered Apr 11 '15 at 11:59 Peter Kämpf 174k1515 gold badges441441 silver badges707707 bronze badges