Dissertations / Theses: 'High-lift design'

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Trapani, Giuseppe. "The design of high lift aircraft configurations through multi-objective optimisation." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/8831.

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An approach is proposed in this work to support the preliminary design of High-Lift aircraft configurations through the use of Multi-Objective optimisation tech¬niques. For this purpose a framework is developed which collates a Free-Form De¬formation parametrisation technique, a number of Computational Fluid Dynamics suites of different fidelity levels, a rapid aero-structure coupling procedure and two multi-objective optimisation techniques, namely Multi-Objective Tabu Search and Non-dominated Sorting Genetic Algorithm-II. The proposed optimisation framework is used for the execution of several design studies. Firstly, the deployment settings and elements' shape of the 2D multi-element GARTEUR A310 test case are optimised for take-off conditions. Consider¬able performance improvements are achieved using both the optimisation algorithms, though the sensitivity of the optimum designs to changes in operating conditions is highlighted. Therefore, a new optimisation set-up is proposed which successfully identifies operational robust designs. Secondly, the framework is extended to the optimisation of 3D geometries, using a Quasi-three-dimensional approach for the evaluation of the aerodynamic performance. The application to the deployment settings optimisation of the (DLF F11) KH3Y configuration illustrates that the method can be applied to more complicated real-world design cases. In particular, the deployment settings of slat and flaps (inboard and outboard segments) are suc¬cessfully optimised for landing conditions. Finally, a rapid aero-structure coupling procedure is implemented, in order to perform static aero-elastic analysis within the optimisation process. The KH3Y optimisation study is repeated including, this time, the effects of structural deformations. Different optima deployment settings are identified compared to the rigid case, illustrating that, despite being of reduced magnitude, wing deformations influence the optimum high-lift system settings. Furthermore, an industrial development and application of multi-objective opti-misation techniques is also presented. In the proposed approach, a reduced order model based on Proper Orthogonal Decomposition methods is used in an offline-online optimisation strategy. The results of the optimisation process for the RAE2822 single-element aerofoil and for the GARTEUR A310 multi-element aerofoil illustrate the potential of the method, as well as its limitations. The technical analysis is com-pleted with a description of the Agile project management approach used to run the project. Finally, future work directions have been identified and recommended.

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McQuilling, Mark W. "DESIGN AND VALIDATION OF A HIGH-LIFT LOW-PRESSURE TURBINE BLADE." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1189792837.

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Ammoo, Mohd Shariff. "Development of a design methodology for transport aircraft variable camber flaps suitable for cruise and low-speed operations." Thesis, Cranfield University, 2003. http://dspace.lib.cranfield.ac.uk/handle/1826/11062.

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This thesis describes the development of a generic design methodology for variable camber flap systems for transport aircraft, intended to be used for cruise and low-speed operations. The methodology was structured after several revisions were performed on conventional high-lift device design methodologies for existing transport aircraft. The definition and detail explanations are given at every phase of the methodology. A case study was performed in order to give an example of the implementation of the methodology where a transport aircraft called A TRA, a design study from previous PhD report, was taken as a model. Experimental work could not be performed, due to budget constraints, so the case study was only carried out using computer-based analyses. Software packages such as MSES-code (a Computational Fluid Dynamic software), CATIA and PATRANINASTRAN were used for this case study to analyse aerodynamic characteristics, layout as well as simulation and structure analyses respectively. The results obtained showed that it was practically feasible to deploy such a high-lift device to transport aircraft when the effect from aerodynamic loads gave minimum effect on structural deformation. The deflections of the flap as well as spoilers under critical loads were below the allowable limits, which had a minimal effect due to the additional lift force generated from the movable surfaces.

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Takai, Tomohiro. "Simulation based design for high speed sea lift with waterjets by high fidelity urans approach." Thesis, University of Iowa, 2010. https://ir.uiowa.edu/etd/748.

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Li, Daxin. "Multi-objective design optimization for high-lift aircraft configurations supported by surrogate modeling." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8468.

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Nowadays, the competition among airlines seriously depend upon the saving operating costs, with the premise that not to degrade its services quality. Especially in the face of increasingly scarce oil resources, reducing fleets operational fuel consumption, is an important means to improve profits. Aircraft fuel economy is determined by operational management strategies and application technologies. The application of technologies mainly refers to airplane’s engine performance, Weight efficiency and aerodynamic characteristics. A market competitive aircraft should thoroughly consider to all of these aspects. Transport aircraft aerodynamic performance mainly is determined by wing’s properties. Wings that are optimized for efficient flight in cruise conditions need to be fitted with powerful high-lift devices to meet lift requirements for safe takeoff and landing. These high-lift devices have a significant impact on the total airplane performance. The aerodynamic characteristics of the wing airfoil will have a direct impact on the aerodynamic characteristics of the wing, and the wing’s effective cruise hand high-lift configuration design has a significant impact on the performance of transport aircraft. Therefore, optimizing the design is a necessary airfoil design process. Nowadays engineering analysis relies heavily on computer-based solution algorithms to investigate the performance of an engineering system. Computational fluid dynamics (CFD) is one of the computer-based solution methods which are more widely employed in aerospace engineering. The computational power and time required to carry out the analysis increases as the fidelity of the analysis increases. Aerodynamic shape optimization has become a vital part of aircraft design in the recent years. Since the aerodynamic shape optimization (ASO) process with CFD solution algorithms requires a huge amount of computational power, there is always some reluctance among the aircraft researchers in employing the ASO approach at the initial stages of the aircraft design. In order to alleviate this problem, statistical approximation models are constructed for actual CFD algorithms. The fidelity of these approximation models are merely based on the fidelity of data used to construct these models. Hence it becomes indispensable to spend more computational power in order to convene more data which are further used for constructing the approximation models. The goal of this thesis is to present a design approach for assumed wing airfoils; it includes the design process, multi-objective design optimization based on surrogate modelling. The optimization design stared from a transonic single-element single-objective optimization design, and then high-lift configurations were two low-speed conditions of multi-objective optimization design, on this basis, further completed a variable camber airfoil at low speed to high-lift configuration to improve aerodynamic performance. Through this study, prove a surrogate based model could be used in the wing airfoil optimization design.

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Burnazzi, Marco [Verfasser], and Rolf [Akademischer Betreuer] Radespiel. "Design of Efficient High-Lift Configurations with Coanda Flaps / Marco Burnazzi ; Betreuer: Rolf Radespiel." Braunschweig : Technische Universität Braunschweig, 2017. http://d-nb.info/1175817937/34.

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Melin, Tomas. "Multidisciplinary Design in Aeronautics, Enhanced by Simulation-Experiment Synergy." Doctoral thesis, Stockholm : Kungliga Tekniska högskolan, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3996.

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Atkins, D. W. "The CFD assisted design and experimental testing of a wing-sail with high lift devices." Thesis, University of Salford, 1996. http://usir.salford.ac.uk/14811/.

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A wingsail is a solid symmetrical aerofoil section which creates thrust in the same manner as a conventional sail. Wingsails may either be used as a sole power unit, e. g. for a yacht or catamaran, or as an auxiliary power unit on a larger craft, e. g. fishing vessels, cargo ships or passenger liners. To augment the thrust created by the wingsail, high lift devices are employed to increase both the maximum lift and the stall incidence of the aerofoil. A wingsail must be symmetrical and capable of creating an equal lift force with the flow approaching the leading edge from either side of the wing centreline, i. e. the wingsail surface must act as either the upper, or lower pressure surface. Initial experimental work proved that using a symmetrical slat as a leading edge high lift device both delayed the separation of flow over the wingsail upper surface and increased the effective camber of the aerofoil. To increase the thrust created still further, this leading edge high lift device was combined with a trailing edge high lift device, a symmetrical single slotted flap. Due to the large number of possible model configurations, a commercially available CFD package was introduced to assist with the design. A series of validation tests comparing the CFD with published and experimental results showed a qualitative agreement with these results. However, the CFD predictions were not sufficiently accurate to be used quantitatively. The computationally designed triple element model was tested experimentally. Lift, drag, pitching moment and pressure distribution measurements were taken from the model. The results of this testing showed that the triple element wingsail increased the plain wing Coax by 68% and the stall incidence by between 4* and 6'. The final triple element wingsail design also increased the thrust of a plain wingsail over the whole operating region. Thrust was increased by up to 83% at the wind angles where a wingsail is most efficient. The results also proved that a commercially available CFD package can be used as an effective and time saving tool for wingsail design.

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Dickel, Jacob Allen. "Design Optimization of a Non-Axisymmetric Endwall Contour for a High-Lift Low Pressure Turbine Blade." Wright State University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=wright1534980581177159.

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Teichel, Sönke [Verfasser], and Jörg [Akademischer Betreuer] Seume. "Optimized design of mixed flow compressors for an active high-lift system / Sönke Teichel ; Betreuer: Jörg Seume." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2018. http://d-nb.info/1168379946/34.

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Teichel, Sönke Holger [Verfasser], and Jörg [Akademischer Betreuer] Seume. "Optimized design of mixed flow compressors for an active high-lift system / Sönke Teichel ; Betreuer: Jörg Seume." Hannover : Gottfried Wilhelm Leibniz Universität Hannover, 2018. http://nbn-resolving.de/urn:nbn:de:101:1-2018100402073813910358.

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12

Yu, Jie. "Novel swing arm mechanism design for trailing edge flaps on commercial airliner." Thesis, Cranfield University, 2008. http://dspace.lib.cranfield.ac.uk/handle/1826/9586.

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This thesis will describe the works had been done by the author in the Flying Crane aircraft group design project and the new design of a novel swing arm mechanism which can be applied in the trailing edge high lift devices for this aircraft concept. Flying Crane aircraft is a new generation commercial airliner concept as the result of group design project conducted by China Aviation Industry Corporation I (AVIC I) and Cranfield University. At the end of the group design project, parameters such as take-off and landing distance, trailing edge flap type and deflection in take-off and landing configuration of the Flying Crane concept have been determined. These parameters are design input of the novel trailing edge high lift device mechanism for this aircraft concept. The idea of this innovative mechanism comes from the research achievement of a previous MSc student, Thomas Baxter, which applied swing arm mechanism into a passenger aircraft's leading edge slat. This thesis applied this idea to trailing edge flap and modeled the mechanism on CATIA software to yield a kinematic simulation for the purpose of check motion trail and force transfer in this mechanism. Relevant works such as actuation, mass and stress analysis are also involved. As the result of this research project, it was found that swing arm mechanism trends to require relatively small fairings for supports and attachments due to its high stowed space utilizing efficiency. Initial mass estimation carried out in this thesis also indicates that the new design takes advantage in terms of weight comparing with traditional trailing edge flap mechanisms. Thus. swing arm mechanism is supposed to show great competitive potential for commercial airliner's trailing edge flaps after further analysis has been done in the detail design phase.

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Martins, Pires Rui Miguel. "Design methodology for wing trailing edge device mechanisms." Thesis, Cranfield University, 2007. http://hdl.handle.net/1826/3393.

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Over the last few decades the design of high lift devices has become a very important part of the total aircraft design process. Reviews of the design process are performed on a regular basis, with the intent to improve and optimize the design process. This thesis describes a new and innovative methodology for the design and evaluation of mechanisms for Trailing Edge High-Lift devices. The initial research reviewed existing High-Lift device design methodologies and current flap systems used on existing commercial transport aircraft. This revealed the need for a design methodology that could improve the design process of High-Lift devices, moving away from the conventional "trial and error" design approach, and cover a wider range of design attributes. This new methodology includes the use of the innovative design tool called SYNAMEC. This is a state-of-the-art engineering design tool for the synthesis and optimizations of aeronautical mechanisms. The new multidisciplinary design methodology also looks into issues not usually associated with the initial stages of the design process, such as Maintainability, Reliability, Weight and Cost. The availability of the SYNAMEC design tool and its ability to perform Synthesis and Optimization of mechanisms led to it being used as an important module in the development of the new design methodology. The SYNAMEC tool allows designers to assess more mechanisms in a given time than the traditional design methodologies. A validation of the new methodology was performed and showed that creditable results were achieved. A case study was performed on the ATRA - Advance Transport Regional Aircraft, a Cranfield University design project, to apply the design methodology and select from within a group of viable solutions the most suitable type of mechanism for the Variable Camber Wing concept initially defined for the aircraft. The results show that the most appropriate mechanism type for the ATRA Variable Camber Wing is the Link /Track Mechanism. It also demonstrated how a wide range of design attributes can now be considered at a much earlier stage of the design.

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Bauer, Matthias [Verfasser], Wolfgang [Akademischer Betreuer] Nitsche, and Heribert [Akademischer Betreuer] Bieler. "Design and application of a fluidic actuator system for high lift flow control / Matthias Bauer. Gutachter: Wolfgang Nitsche ; Heribert Bieler. Betreuer: Wolfgang Nitsche." Berlin : Technische Universität Berlin, 2015. http://d-nb.info/1074912330/34.

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15

Elahipanah, Hossein. "Design Optimization and Realization of 4H-SiC Bipolar Junction Transistors." Doctoral thesis, KTH, Elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-211659.

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4H-SiC-based bipolar junction transistors (BJTs) are attractive devices for high-voltage and high-temperature operations due to their high current capability, low specific on-resistance, and process simplicity. To extend the potential of SiC BJTs to power electronic industrial applications, it is essential to realize high-efficient devices with high-current and low-loss by a reliable and wafer-scale fabrication process. In this thesis, we focus on the improvement of the 4H-SiC BJT performance, including the device optimization and process development. To optimize the 4H-SiC BJT design, a comprehensive study in terms of cell geometries, device scaling, and device layout is performed. The hexagon-cell geometry shows 42% higher current density and 21% lower specific on-resistance at a given maximum current gain compared to the interdigitated finger design. Also, a layout design, called intertwined, is used for 100% usage of the conducting area. A higher current is achieved by saving the inactive portion of the conducting area. Different multi-step etched edge termination techniques with an efficiency of >92% are realized. Regarding the process development, an improved surface passivation is used to reduce the surface recombination and improve the maximum current gain of 4H-SiC BJTs. Moreover, wafer-scale lift-off-free processes for the n- and p-Ohmic contact technologies to 4H-SiC are successfully developed. Both Ohmic metal technologies are based on a self-aligned Ni-silicide (Ni-SALICIDE) process. Regarding the device characterization, a maximum current gain of 40, a specific on-resistance of 20 mΩ·cm2, and a maximum breakdown voltage of 5.85 kV for the 4H-SiC BJTs are measured. By employing the enhanced surface passivation, a maximum current gain of 139 and a specific on-resistance of 579 mΩ·cm2 at the current density of 89 A/cm2 for the 15-kV class BJTs are obtained. Moreover, low-voltage 4H-SiC lateral BJTs and Darlington pair with output current of 1−15 A for high-temperature operations up to 500 °C were fabricated. This thesis focuses on the improvement of the 4H-SiC BJT performance in terms of the device optimization and process development for high-voltage and high-temperature applications. The epilayer design and the device structure and topology are optimized to realize high-efficient BJTs. Also, wafer-scale fabrication process steps are developed to enable realization of high-current devices for the real applications.

QC 20170810

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16

von, Stillfried Florian. "Computational studies of passive vortex generators for flow control." Licentiate thesis, KTH, Mechanics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-11737.

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Many flow cases in fluid dynamics face undesirable flow separation due torising static pressure on wall boundaries. This occurs e.g. due to geometry as ina highly curved turbine inlet duct or e.g. on flow control surfaces such as wingtrailing edge flaps within a certain angle of attack range. Here, flow controldevices are often used in order to enhance the flow and delay or even totallyeliminate flow separation. Flow control can e.g. be achieved by using passiveor active vortex generators (VG) that enable momentum mixing in such flows.This thesis focusses on passive VGs, represented by VG vanes that are mountedupright on the surface in wall-bounded flows. They typically have an angle ofincidence to the mean flow and, by that, generate vortex structures that in turnallow for the desired momentum mixing in order to prevent flow separation.A statistical VG model approach, developed by KTH Stockholm and FOI,the Swedish Defence Research Agency, has been evaluated computationally.Such a statistical VG model approach removes the need to build fully resolvedthree-dimensional geometries of VGs in a computational fluid dynamics mesh.Usually, the generation of these fully resolved geometries is rather costly interms of preprocessing and computations. By applying this VG model, thecosts reduce to computations without VG effects included. Nevertheless, theVG model needs to be set up in order to define the modelled VG geometry inan easy and fast preprocessing step. The presented model has shown sensitivityfor parameter variations such as the modelled VG geometry and the VG modellocation in wall-bounded zero pressure gradient and adverse pressure gradientflows on a flat plate, in a diffuser, and on an airfoil with its high-lift systemextracted. It could be proven that the VG model qualitatively describes correcttrends and tendencies for these different applications.

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Zhou, Zhengquan. "A theory and analysis of planing catamarans in calm and rough water." ScholarWorks@UNO, 2003. http://louisdl.louislibraries.org/u?/NOD,45.

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Thesis (Ph.D)--University of New Orleans, 2003.
Title from electronic submission form. "A dissertation ... in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Engineering and Applied Science"--Dissertation t.p. Vita. Includes bibliographical references.

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18

Chu, Hao-Kun, and 朱浩坤. "A Design Method of High Lift Airfoil." Thesis, 1999. http://ndltd.ncl.edu.tw/handle/62520957668948480130.

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碩士
國立成功大學
航空太空工程學系
87
ABSTRACT Subject : A Design Method of High Lift Airfoil Student : Hao-Kun Chu Advisor : Sheng-Jii Hsieh A method of inverse airfoil design for incompressible potential flow presented by Selig and Maughmer is used in this study. The problem, from a given surface velocity distribution determine the corresponding airfoil shape, is solved by conformal mapping method. After determining the relation of mapping, one may compute the airfoil shape from the unit circle. The prescription of upper surface velocity distribution obeys the Liebeck''s high lift laws, including constant-velocity region, followed by a Stratford-type zero-skin-friction portion to ensure the flow unseparate when decelerates, and ensure the average velocity of upper surface as large as possible. By assuming an initial input of lower surface velocity distribution, and then modifying a portion of the lower surface by the use of least squares and Lagrangian multipliers, one can ensure the velocity distribution satisfies the constraints of inverse method, and minimizes the profile of closure condition. Two high lift airfoils are designed respectively for airfoil trailing-edge angle 0°and 16°, with angle of attack α= 8°. In corporated with the vortex panel method, one may obtain the relation of lift coefficient and angle of attack, and get the maximum lift coefficient and maximum lift-to-drag ratio , for each designed high lift airfoil. For the first high lift airfoil (zero trailing-edge angle case), the stall angle of attack is α=20°, and the maximum lift coefficient is 2.05, but the lift-to-drag ratio is only 24.37. However, when α=8°, the lift coefficient is 1.57, but there has maximum lift-to-drag ratio 73.52. For the second high lift airfoil (trailing-edge angle 16°case), the stall angle of attack is α=15°, and the maximum lift coefficient is 1.735, but the lift-to-drag ratio is only 10.73. However, whenα= 10°, the lift coefficient is 1.55, but there has lift-to drag ratio 82.03,. This study provides a practical computer program for high lift airfoil design, but for the calculation of lower surface velocity distribution, one should search better method to deal with the singularity around leading edge, so as to obtain the problem resulting of high lift but low lift-to-drag ratio.

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19

Chih-HaoLien and 連志豪. "High-Lift UAV Airfoil Design and Verification." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/09799756527653973483.

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碩士
國立成功大學
航空太空工程學系碩博士班
100
The feasibility design and evaluation of high-lift devices on Ce-71 series UAV is performed by experimental method. With precision model fabrication, the experiments of high-pressure smoke flow visualization is carried out in a suction type low-speed wind tunnel. The controlling factors on AoA of main wing, the flap deflection, the area of control surface and Reynolds number are changed to obtain visualization results. This research starts from wing design and manufacture as the wind tunnel experiment model for wing flow visualization experiment. The high-lift wings are then set on the Tiger II trainer for flight test verifications. Flight test records on relative variation of height and speed are collected for verification. The relationship between control surface to UAV lift provides further development guideline for better flight performance in Ce-71 series.

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Wu, Cheng-Fang, and 吳承芳. "An Investigation on High-Lift Airfoil Design Method." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/16184202820069965889.

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碩士
國立成功大學
航空太空工程學系
89
ABSTRACT Subject: An Investigation on High-Lift Airfoil Design Method Student: Cheng-Fang Wu Advisor: Sheng-Jii Hsieh A method of inverse airfoil design for incompressible potential flow presented by Selig and Maughmer is applied in this study. This multi- point design method makes use of the conformal mapping to compute the airfoil shape from the unit circle, and one can compute the airfoil with zero or finite trailing-edge angle. The principle of upper-surface velocity distribution employs the Liebeck’s high-lift concept, and uses Stratford type zero-skin-friction requirement at pressure recovery region to assure the boundary layer unseparated flow condition. In order to meet the high-lift demand, it is necessary to ensure the average velocity of upper surface as large as possible, but the average velocity of lower surface is otherwise oppositely. By assuming an initial lower-surface velocity distribution, and then modifying a portion of the lower surface velocity distribution by sine series function where the coefficients are determined by the least squares and the Lagrangian multipliers. One can assure the lower surface velocity distribution satisfies the constraints of inverse airfoil design method, and have the modified distribution as closed to the initial input as possible. In this study the angle of attack(α), the trailing-edge velocity ( ),the length of accelerating region( ), the orthogonal functions numbers(n) and the airfoil design points(N) will be discussed. From this investigation two high-lift airfoils are designed respectively for the trailing-edge angle 0°withα= 8°and the trailing-edge angle 16°withα= 9°. For the first case (zero trailing-edge angle case), whenα= 8°, ＝0.95, ＝0.05, n＝50, N＝60, the designed high-lift airfoil can be obtained with the lift coefficient =1.2264, the drag coefficient =0.03408 and the lift/drag ratio =35.98. For the second case (trailing-edge angle 16°case), whenα= 9°, ＝0.95, ＝0.05, n＝50, N＝86, the designed high-lift airfoil can be obtained with =2.1187, =0.01819 and =116.48.

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Huang, Bo-Cheng, and 黃柏誠. "Design and Fabrication for Modular High-lift UAV Device." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/70862630332867600600.

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碩士
中華科技大學
航空機械系飛機系統工程碩士班
103
Present study designs and fabrication the modular high-lift device used for UAV when execute disaster task. Device was designed to construct on the belly of UAV and has individually control, actuator and power supply systems. The active attitude feedback system was developed by Arduino development broad and MPU-6050 electric gyro. It can automatically adjust attitude of high-lift wing based on the aircraft attitude variation to supply additional lift and a Li-Po battery was used for long time operation. Appearance was developed by CATIA and simulates actuation of all subsystems. The main structure and wing were made by balsa wood and strengthened by glass fiber. This work also used common commercial plastic fastener to connect to UAV and the aerodynamic properties were modified via the smoke flow wind tunnel experiments to reduce appearance drag. Finally, present system will be tested to confirm its practicability.

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Gopalakrishna, N. "On Three Dimensional High Lift Flow Computations." Thesis, 2014. http://hdl.handle.net/2005/3127.

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Computing 3D high lift flows has been a challenge to the CFD community because of three important reasons: complex physics, complex geometries and large computational requirements. In the recent years, considerable progress has been made in understanding the suitability of various CFD solvers in computing 3D high lift flows, through the systematic studies carried out under High Lift Prediction workshops. The primary focus of these workshops is to assess the ability of the CFD solvers to predict CLmax and αmax associated with the high lift flows, apart from the predictability of lift and drag of such flows in the linear region. Now there is a reasonable consensus in the community about the ability of the CFD solvers to predict these quantities and fresh efforts to further understand the ability of the CFD solvers to predict more complex physics associated with these flows have already begun. The goal of this thesis is to assess the capability of the computational methods in predicting such complex flow phenomena associated with the 3D High-Lift systems. For evaluation NASA three element Trapezoidal wing configuration which poses a challenging task in numerical modeling was selected. Unstructured data based 3D RANS solver HiFUN (HiFUN stands for High Resolution Flow Solver for UNstructured Meshes) is used in investigating the high lift flow. The computations were run fully turbulent, using the one equation Spalart-Allmaras turbulence model. A summary of the results obtained using the flow solver HiFUN for the 3D High lift NASA Trapezoidal wing are presented. Hybrid unstructured grids have been used for the computations. Grid converged solution obtained for the clean wing and the wing with support brackets, are compared with experimental data. The ability of the solver to predict critical design parameters associated with the high lift flow, such as αmax and CLmax is demonstrated. The utility of the CFD tools, in predicting change in aerodynamic parameters in response to perturbational changes in the configuration is brought out. The solutions obtained for the high lift configuration from two variants of the Spalart-Allmaras turbulence model are compared. To check the unsteadiness in the flow, particularly near stall, unsteady simulations were performed on static grid. Lastly, hysteresis on lower leg of lift curve is discussed, the results obtained for quasi-steady and dynamic unsteady simulations are presented. Inferences from the study on useful design practices pertaining to the 3D high lift flow simulations are summarized.

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Dissertations / Theses on the topic 'High-lift design'

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