An evolutionary geometry parametrization is established to represent aerodynamic configurations. This geometry parametrization technique is constructed by integrating the classical B-spline formulation with the knot insertion algorithm. It is capable of inserting control points to a given parametrization without modifying its geometry. Taking advantage of this technique, a shape design problem can be solved as a sequence of optimizations from the basic parametrization to more refined parametrizations. Owing to the nature of the B-spline formulation, feasible parametrization refinements are not unique; guidelines based on sensitivity analysis and geometry constraints are developed to assist the automation of the proposed optimization sequence. Test cases involving airfoil optimization and induced drag minimization are solved adopting this method. Its effectiveness is demonstrated through comparisons with optimizations using uniform refined parametrizations.

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Several programs exist today for calculating aerodynamic coefficients that with some simplificationsprovide fast approximations of the values for a real aircraft.Four different programs were analyzed for this report: Tornado, AVL, PANAIR and a handbook-typepreliminary method. In addition, ANSYS CFX was used for airfoil validation. For calculation of the zerolift drag, an approximation was computed in order to calculate the remaining values that were notcalculated by the software: drag contribution for fuselages, nacelles and some horizontal stabilizersand fins.Different types of aircraft were selected for trial: two commercial aircraft (Boeing 747-100 and 777-300), a TF-8A research airplane (with area rule application: some additions were made to the fuselageto prevent large variations in the cross-section when the contribution of the wing is added), a LockheedConstellation C-69 used as a military cargo airplane, a Boeing Stratocruiser used by the USAF withtwo configurations (basic and bomber), and an Aero Commander 680 Super, similar to a Cessna 162.Two airfoils (NACA2412, 0012) were also analyzed, to investigate the limitations of software designedfor three-dimensional calculations.The accuracy of the results showed that the validity of the software depends on the planform of theaircraft, as well as the simulation parameters Mach number and Reynolds number. The shape of thewing caused some of the methods to have serious difficulties in converging to valid results, orincreased the simulation time beyond acceptable limits. / Numera finns det olika program för beräkning av de aerodynamiska koefficienterna från en modellmed vissa förenklingar som ger en snabb approximation av värdena för ett verkligt flygplan.Fyra olika program har analyserats för denna rapport: Tornado, AVL, PANAIR och en handbokbaserad preliminär metod. Dessutom användes ANSYS CFX för validering av vingprofiler . Vidberäkningen av noll-lyft motståndet, en approximation användes för de återstående delarna som inteberäknas av de andra metoderna: motståndsbidraget från flygkroppar, gondoler och vissa horisontellastabilisatorer och fenor.Olika flygplaner har testats: två trafikflygplan (Boeing 747-100 och 777-300), ett TF-8Aforskningsflygplan (med area regel användning: några tillägg gjordes på flygkroppen för att tvärsnitteninte har stora variationer när bidraget från vingen läggas), ett Lockheed Constellation C-69, ett BoeingStratocruiser som används av USAF i två konfigurationer (den vanliga och bombplan), och ett AeroCommander 680 Super, som liknar ett Cessna 162. Två vingprofiler (NACA 2412, 0012) analyseradesockså, för att kontrollera begränsningarna av programmen avsedd för tredimensionella beräkningar.Riktigheten av resultaten visade att giltigheten av programmen beror på formen av flygplanernasvingar, samt de simulationernas parametrar: Mach nummer och Reynolds nummer. Formen på vingenorsakade några av de metoderna att ha stora svårigheter med konvergensen till giltiga resultat, ellerökat simulering tid över acceptabla gränser.

Air inlets in some form are used on all commercial airliners today. The type of air inlet investigated in this report is a NACA inlet submerged into a surface. This surface is within this thesis a test section wall of a wind tunnel. The considered wind tunnel is TWG in Göttingen (Germany) that operates in transonic speeds. Submerged inlets have the main advantage of low aeroynamic drag from the inlet itself. The importance of reducing drag, and the attention given to this subject is increasing as fuel prices rise as well as public awareness of environmental impact by all of us. The outcome of this thesis contributes to the government-funded project ECOCENTS which deals with the design of innovative new aircraft cooling systems and the detailed flow analysis of these systems. This thesis was carried out at the company Airbus in Bremen, Germany. The main objective of this report was the evaluation of the ram pressure efficiency of four different ramp angles of a NACA inlet and the estimation of the drag caused by these geometries with the use of Computational Fluid Dynamics (CFD). The flow solver used was TAU, a Reynolds-Averaged Navier-Stokes (RANS) solver developed by the German Aerospace Center (DLR). The inlet consisted of one ramp section where the ramp angle was fixed at 7 degrees, and a second variable ramp section. The following different angles were investigated: 4, 7, 10 and 15 degrees. These configurations were evaluated at a velocity of Mach 0.8 and a Reynolds number of 10*10^6. The ramp angle of 7 degrees was evaluated at two additional velocities (Mach 0.73 and Mach 0.87) and at two additional Reynolds numbers (5*10^6 and 15*10^6) at Mach 0.8. The inlet efficiency outcome of this study was located between two other investigations. The results of this RANS computation predicted a higher total pressure at the inlet throat plane compared to a previous CFD investigation where a different RANS solver at the same geometry was used. In comparison to an estimation method mainly based on experimental data (ESDU method), the recent study showed a lower total pressure at the inlet throat plane. The aerodynamic drag that arised by the presence of the inlet system was calculated within this thesis to be higher than the outcome of the experimental data based (ESDU) method. The advantage of using a NACA type inlet was observed to be highly related to the ramp angle. Vortices are originated and develop along the edges of the intake ramp walls. These two vortices help to transport higher energy flow from the free stream into the inlet and therefore reduce the boundary layer thickness in the inlet region. For lower mass flows (0.10 - 0.20 kg/s) a ramp angle of 7 degrees was seen to be prefered in view of ram pressure efficiency. At a higher mass flow (0.25 kg/s) the 10 degrees ramp angle was prefered, followed by the 15 degrees ramp angle at the highest investigated mass flows (0.30 - 0.35 kg/s). In view of drag, the lowest ramp angle possible for a given mass flow was seen to be most advantagous. Future work on this subject will include simulation of an inlet in combination with a heat exchanger and a ram air outlet. This arrengement will be the same as in the investigation at the TWG test campaign and therefore comparable. The difference in outcome of the separate CFD analysis was discussed within this investigation but could not be completely cleared.

Thesis (M.S.)--Mississippi State University. Department of Aerospace Engineering. / Title from title screen. Includes bibliographical references.

Thesis--Auburn University, 2009. / Abstract. Includes bibliographic references (p.70-72).

Galloping of structures such as transmission lines and bridges is a classical aeroelastic instability that has been considered as harmful and destructive. However, there exists potential to harness useful energy from this phenomenon. The study presented in this paper focuses on harvesting wind energy that is being transferred to a galloping beam. The beam has a rigid prismatic tip body. Triangular and D-section are the two kinds of cross section of the tip body that are studied, developed and tested. Piezoelectric sheets are bonded on the top and bottom surface of elastic portion of the beam. During galloping, vibrational motion is input to the system due to aerodynamic forces acting on the tip body. This motion is converted into electrical energy by the piezoelectric (PZT) sheets. A potential application for this device is to power wireless sensor networks on outdoor structures such as bridges and buildings. The relative importance of various parameters of the system such as wind speed, material properties of the beam, electrical load, beam natural frequency and aerodynamic geometry of the tip body is discussed. A model is developed to predict the dynamic response, voltage and power results. Experimental investigations are performed on a representative device in order to verify the accuracy of the model as well as to study the feasibility of the device. A maximum output power of 1.14 mW was measured at a wind velocity of 10.5 mph. / text

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