Apparatus for twisting a wing to increase lift on aircraft and other vehicles
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
B64C-003/14
B64C-003/52
출원번호
US-0987231
(2011-01-10)
등록번호
US-8262030
(2012-09-11)
발명자
/ 주소
Phillips, Warren F.
출원인 / 주소
Utah State University
인용정보
피인용 횟수 :
1인용 특허 :
4
초록▼
A method and apparatus for varying the twist of a wing such that induced drag is minimized or reduced during cruise and lift is maximized or increased at least during takeoff and landings. In addition, variations in the twist may produce yawing and rolling moments. The twist amount is varied pursuan
A method and apparatus for varying the twist of a wing such that induced drag is minimized or reduced during cruise and lift is maximized or increased at least during takeoff and landings. In addition, variations in the twist may produce yawing and rolling moments. The twist amount is varied pursuant to the operating conditions, including those parameters used to determine the lift coefficient. The twist for reducing induced drag and/or improving lift may be employed by geometric or aerodynamic twist, including full span control surfaces used to provide roll control, high-lift and reduced induced drag. The twist may also be employed by twisting just a portion of the wing or the entire wing, either geometrically or aerodynamically.
대표청구항▼
1. A vehicle comprising; a wing;a twistable portion on the wing; anda control system for implementing a first twist distribution and a second twist distribution in the twistable portion of the wing;wherein the control system is able to vary twist amount for the first and second twist distributions t
1. A vehicle comprising; a wing;a twistable portion on the wing; anda control system for implementing a first twist distribution and a second twist distribution in the twistable portion of the wing;wherein the control system is able to vary twist amount for the first and second twist distributions to implement a twist distribution based, at least in part, upon an equation, the equation being ω(θ)=F(π/2)-F(θ)F(π/2)-F(0) where F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθ and where ω(θ) is the twist distribution b is a wingspan, {tilde over (C)}L,α is an airfoil section lift slope, c(θ) is a local airfoil section chord length at θ, θ is equal to cos−1(−2z/b) where z is a spanwise coordinate and b is a wingspan, {tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, and CL is a lift coefficient of the wing. 2. The vehicle of claim 1 wherein the first twist distribution is operable to minimize or reduce induced drag on the wing and the second distribution is operable to maximize or increase lift generated by the wing. 3. The vehicle of claim 1, further comprising a computer for calculating the twist amount. 4. The vehicle of claim 3, further comprising at least one sensor for monitoring operating conditions, the at least one sensor feeding information on the operating conditions to the computer, and using the information by the computer to calculate the twist amount. 5. The vehicle of claim 4, wherein the at least one sensor is configured to monitor a airspeed of the vehicle. 6. The vehicle of claim 4 wherein the at least one sensor is configured to monitor air density. 7. The vehicle of claim 4, wherein the at least one sensor is configured to monitor a load factor. 8. The vehicle of claim 1, wherein the control system comprises an electronic memory, said electronic memory having stored therein a software program for calculating the twist amount. 9. The vehicle of claim 8, wherein the first and second twist distributions are stored in the electronic memory. 10. The vehicle of claim 8, wherein the electronic memory has a software program stored therein for calculating a lift coefficient. 11. The vehicle of claim 1, wherein at least one of the first and second twist distributions maintains a nearly uniform airfoil section lift coefficient distribution over the twistable portion of the wing. 12. The vehicle of claim 1, wherein at least one of the first and second twist distributions maximizes an airfoil section lift coefficient distribution over the twistable portion of the wing. 13. The vehicle of claim 1, wherein the twist amount for the first and second twist distribution is varied while the vehicle is in operation. 14. The vehicle of claim 1 wherein the twist amount for at least one of the first and second twist distributions is calculated by the control system using an equation, the equation being Ω=[F(π/2)−F(0)]CL where F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθand whereΩ is the twist amount,b is a wingspan,{tilde over (C)}L,α is an airfoil section lift slope,c(θ) is a local airfoil section chord length at θ,θ is equal to cos−1(−2z/b) where z is a spanwise coordinate andb is a wingspan,{tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, andCL is a lift coefficient of the wing. 15. The vehicle of claim 1, wherein at least one of the first and second twist distributions is determined by an equation, the equation being ω(z)=1-1-(2z/b)2c(z)/crootwhere ω(z) is said second twist distribution, z is a distance from a root of the wing, b is a wingspan, c(z) is a local wing section chord length, and croot is a root wing section chord length. 16. The vehicle of claim 1, wherein at least one of the first and second twist distributions is determined by an equation, the equation being ω(θ)=1-sin(θ)c(θ)/crootwhere ω(θ) is said second twist distribution, θ is equal to cos−1(−2z/b} where z is a distance from a root of the wing and b is a wingspan. 17. The vehicle of claim 1 wherein the twist amount for at least one of the first and second twist distributions is calculated by the control system using an equation, the equation being (δt)opt=2(1+RT)CLπC~L,αɛfThere (δt)OPT is the twist amount, RT is a wing taper ratio, cL, is a lift coefficient, {tilde over (C)}L,α is an airfoil section lift slope, and εf is a local airfoil section flap effectiveness. 18. The vehicle of claim 1 wherein the control system calculates the twist amount for at least one of the first and second twist distributions using a lift coefficient for the wing. 19. The vehicle of claim 1 wherein the control system calculates the twist amount for both the first and second twist distributions using a lift coefficient for the wing. 20. A vehicle of claim 1, wherein the control system is able to vary twist amount for the first and second twist distributions to implement a twist distribution within about 0% to 33% of a twist distribution based, at least in part, upon an equation, the equation being ω(θ)=F(π/2)-F(θ)F(π/2)-F(0)where F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθand whereω(θ) is the twist distributionb is a wingspan,{tilde over (C)}L,α is an airfoil section lift slope,c(θ) is a local airfoil section chord length at θ,θ is equal to cos−1(−2z/b) where z is a spanwise coordinate andb is a wingspan,{tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, andCL is a lift coefficient of the wing. 21. A system for twisting a wing of a vehicle, said system comprising: means for determining an amount of twist to be applied to at least a portion of the wing for the purpose of improving lift generated by the wing; and means for applying a twist to said at least a portion of said wing, wherein the twist amount is based, at least in part, by an equation, the equation being Ω=[F(π/2)−F(0)]CL where F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθand whereΩ is the twist amount,b is a wingspan,{tilde over (C)}L,α is an airfoil section lift slope,c(θ) is a local airfoil section chord length at θ,θ is equal to cos−1(−2z/b) where z is a spanwise coordinate andb is a wingspan,{tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, andCL is a lift coefficient of the wing. 22. The system of claim 21, wherein the means for determining an amount of twist to be applied comprises at least one sensor. 23. The system of claim 22, wherein the at least one sensor is configured to determine at least one of the group consisting of a airspeed of the vehicle, a weight of the vehicle, an air density, a load factor, and a wing area. 24. The system of claim 21, wherein the means for determining an amount of twist to be applied comprises a computer for receiving data and calculating said twist amount. 25. The system of claim 21, wherein the means for applying a twist comprises a rod. 26. The system of claim 25, wherein the means for applying a twist includes at least one of the group consisting of a cogwheel, a hydraulic actuator, a mechanical screw actuator, and a rotating shaft. 27. The system of claim 21, wherein the means for applying a twist comprises at least one motor for supplying a rotational force. 28. A system for twisting a wing of a vehicle, said system comprising: a control system for implementing a twist distribution in the wing of the vehicle; wherein the control system is able to vary a twist amount to implement the twist distribution to thereby generate improved lift during operation of the vehicle, wherein the twist distribution is based, at least in part, on an equation, the equation being ω(θ)=F(π/2)-F(θ)F(π/2)-F(0)where F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθand whereω(θ) is the twist distributionb is a wingspan,{tilde over (C)}Lα is an airfoil section lift slope,c(θ) is a local airfoil section chord length at θ,θ is equal to cos−1(−2z/b) where z is a spanwise coordinate andb is a wingspan,{tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, andCL is a lift coefficient of the wing. 29. The vehicle of claim 28, further comprising a computer for calculating the twist amount. 30. The system of claim 29, further comprising at least one sensor for monitoring operating conditions, the at least one sensor feeding information on the operating conditions to the computer, and using the information by the computer to calculate the twist amount. 31. The system of claim 30, wherein the at least one sensor is configured to monitor an airspeed of the vehicle. 32. The system of claim 30, wherein the at least one sensor is configured to monitor air density. 33. The system of claim 30, wherein the at least one sensor is configured to monitor a load factor. 34. The system of claim 28, wherein the control system comprises an electronic memory, said electronic memory having stored therein a software program for calculating the twist amount. 35. The system of claim 34, wherein the twist distribution is also stored in the electronic memory. 36. The system of claim 34, wherein the electronic memory further has a software program stored therein for calculating a lift coefficient. 37. The system of claim 28, wherein the twist distribution maintains a nearly uniform airfoil section lift coefficient distribution over at least a portion of the wing. 38. The system of claim 28, wherein the twist distribution maximizes an airfoil section lift coefficient distribution over at least a portion of the wing. 39. The system of claim 28, wherein the twist amount for the twist distribution is varied while the vehicle is in operation. 40. The system of claim 28 wherein the twist amount for the twist distribution is calculated by the control system using an equation, the equation being Ω=[F(π/2)−F(0)]CL where F(π/2) and F(0) are evaluated using the equations F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθand whereΩ is a twist amount,b is a wingspan,{tilde over (C)}L,α is an airfoil section lift slope,c(θ) is a local airfoil section chord length at θ,θ is equal to cos−1(−2z/b) where z is a spanwise coordinate andb is a wingspan,{tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, andCL is a lift coefficient of the wing. 41. The system of claim 28 wherein the twist amount for the twist distribution is calculated by the control system using an equation, the equation being Ω=xCL where x is a constant and CL is a lift coefficient of the wing. 42. A system of claim 28, wherein the implemented twist distribution is within about 0% to 33% of the twist distribution based, at least in part, on an equation, the equation ω(θ)=F(π/2)-F(θ)F(π/2)-F(0)beingwhere F(θ)=∑n=1∞wn[4bC~L,αC(θ)+nsin(θ)]sin(nθ)wn=12π∫θ=0πc(θ)C~Ld(θ)bCLsin(nθ)ⅆθand whereω(θ) is the twist distributionb is a wingspan,{tilde over (C)}L,α is an airfoil section lift slope,c(θ) is a local airfoil section chord length at θ,θ is equal to cos−1(−2z/b) where z is a spanwise coordinate andb is a wingspan,{tilde over (C)}Ld(θ) is a target airfoil section lift coefficient distribution that is to be produced over the wingspan, andCL is a lift coefficient of the wing.
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이 특허에 인용된 특허 (4)
Tulinius Jan (Huntington Beach CA), Active flexible wing aircraft control system.
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