The thesis deals with aerodynamic characteristics identification from flight measurement. The topic is part of flight mechanic – handling qualities. The first theoretic part consists of three identification methods description: Error equation method, Output error method and Filter error method. Mathematical model of an airplane is defined and restricted to the motion with 3 degree of freedom. There is also introduced simulation of flight measurement for identification software validation. Practical part is focused on experiment preparation, execution and evaluation. The airplane VUT 700 Specto had been chosen to carry out flight tests. The airplane was modified to the new electric powered VUT 700e Specto after first measurement flights with combustion engine. Data record from on-board measurement unit was completed by telemetric data from autopilot and remote control system. Flight tests were carried out in stabilised mode of autopilot in symmetric flight. The results were confronted with analytical analysis results and DATCOM+ software parameter estimation.

This diploma thesis deals with modeling and CFD calculation of aerodynamic characteristics of vehicle, influenced by loaded or unloaded tires and boundary conditions applied on this tires. These calculations are combined with three types of variable rear body shape of DrivAer vehicle. There is a complete analysis and evaluation of the effects of these factors.

Master’s thesis deals with aerodynamic heating of launch vehicle during ascent phase by using CFD simulation. Ascent trajectory and payload fairing geometry is design using data of existing small launch vehicles. Critical flight regimes are identified using 2D calculations, and in these regimes analysis is performed by axially symmetric simulations. Simulation results are compared to values obtained from theoretical and semi-empirical calculations.

Name of Work Comparison of heart-rate, lactate levels, swimming speed in streamlined (aerodynamic) channel and swimming pool. Goal of Work To determine whether the same swimming speed affects the heart-rate and blood lactate in exactly the same way, in both the aerodynamic channel and in the swimming pool. To check the velocity of water flowing in a streamlined channel. Method Data collection (blood lactate, values of heart-rate, speed of swimming) will be done first in the swimming pool and then in the streamlined channel, the so-called FLUM. Probands will swim progressively faster in swimming sections of equal length. To obtain lactate levels, the invasive method will be used. Cardiac frequency will be obtained from heart-rate monitors, which each proband will have mounted on the body throughout testing. To verify the speed of flowing water, measuring equipment (propellers) borrowed from the Czech Agricultural University Prague, will be used. Results The work provides information on whether there is a difference in values or internal performance when comparing the speed in swimming pools with the speed in a streamlined channel. If so, the researcher will create a formula to convert the swimming speed in the aerodynamic channel to the speed level in a swimming pool. To create a formula that would...

The energy exchange in the soil-snow-vegetation-atmospheresystem was studied to improve the quantitative knowledge of thegoverning processes. The lack of such knowledge contributes tothe uncertainty in the applicability of many existing modelsindependent of the temporal or spatial scale. The theoreticalbackground and available methods for measurements and numericalsimulations were reviewed. Numerical simulation models andavailable data sets representing open land and boreal forestwere evaluated in both diurnal and seasonal time-scales.Surface heat fluxes, snow depth, soil temperatures andmeteorological conditions were measured at an agriculturalfield in central Sweden over two winters, 1997-1999. Twoone-dimensional simulation models of different complexity wereused to simulate the heat and water transfer in thesoil-snow-atmosphere system and compared with the measurements.Comparison of simulated and observed heat fluxes showed thatparameter values governing the upper boundary condition weremore important than the formulation of the internal mass andheat balance of the snow cover. The models were useful toevaluate the lack of energy balance closure in the observedsurface heat fluxes, which underlined the importance ofimproved accuracy in eddy correlation measurements of latentflow during winter conditions. The representation of boreal forest in the land surfacescheme used within a weather forecast model was tested with athree-year data set from the NOPEX forest site in centralSweden. The formulation with separate energy balances forvegetation and the soil/snow beneath tree cover improvedsimulation of the seasonal and diurnal variations of latent andsensible heat flux compared with an older model version.Further improvements of simulated surface heat fluxes could beexpected if the variation of vegetation properties within andbetween years and a new formulation of the boundary conditionsfor heat flux into the soil is included. Keywords: Surface energy balance, Snow, Boreal forest,SVAT models, Eddy-correlation Measurements, Latent heat flux,Sensible heat flux, Net radiation, Soil temperature,Aerodynamic roughness, Surface resistance / QC 20100614

One of the early steps in axial turbine design is the use of one-dimensional (1D) mean line calculations to predict the turbine performance and estimate the principal geometric parameters, such as radius and blade heights, that will be needed in further computational fluid dynamic (CFD) studies. This 1D analysis is based on the estimation of the aerodynamic losses expressed as a function of simple blade parameters and the velocity triangles. In this regard, there exist different loss correlations widely used in literature to estimate these losses but at the same time there is a lack of information regarding differentiation between them. Thereafter, the objective in this work was to judge and compare the behaviors of the Kacker- Okapuu, Craig-Cox and Denton loss correlations, all of them widely-used in turbine performance prediction. Present work shows the implementation of these different loss correlations on an existing 1D mean line numerical tool, LUAX-T. Subsequently, once implemented, the correlations were compared and analyzed by the use of a validation process and performing a parametric study. The results show that similar key parameters such as the flow turning, solidity and aspect ratio rule the different loss mechanisms in each correlation. On the other hand, the parametric study shows that the correlations are in agreement with the theory and give similar trends for performance prediction even though they all predict different values of efficiency for the same turbine stage. Moreover, the validation process show the correlations were found to be accurate enough when comparing against two different sets of experimental data. However, it was also proved that the models are only accurate if used within the range of applicability they were developed for, hence a complete knowledge of the limitations of each correlation should be known prior to using them. Finally, the extension of the one-dimensional mean line numerical tool LUAX-T will serve to perform further studies related to turbine design, as there are very few non-confidential turbomachinery design tools available for teaching or researching. Furthermore, a parametric study tool was also developed as part of the program. This last extension and the loss implementation codes are described in this work.

Train transportation is a vital part of the transportation system of today anddue to its safe and environmental friendly concept it will be even more impor-tant in the future. The speeds of trains have increased continuously and withhigher speeds the aerodynamic effects become even more important. One aero-dynamic effect that is of vital importance for passengers’ and track workers’safety is slipstream, i.e. the flow that is dragged by the train. Earlier ex-perimental studies have found that for high-speed passenger trains the largestslipstream velocities occur in the wake. Therefore the work in this thesis isdevoted to wake flows. First a test case, a surface-mounted cube, is simulatedto test the analysis methodology that is later applied to a train geometry, theAerodynamic Train Model (ATM). Results on both geometries are comparedwith other studies, which are either numerical or experimental. The comparisonfor the cube between simulated results and other studies is satisfactory, whiledue to a trip wire in the experiment the results for the ATM do not match.The computed flow fields are used to compute the POD and Koopman modes.For the cube this is done in two regions of the flow, one to compare with a priorpublished study Manhart & Wengle (1993) and another covering more of theflow and especially the wake of the cube. For the ATM, a region containing theimportant flow structures is identified in the wake, by looking at instantaneousand fluctuating velocities. To ensure converged POD modes two methods toinvestigate the convergence are proposed, tested and applied. Analysis of themodes enables the identification of the important flow structures. The flowtopologies of the two geometries are very different and the flow structures arealso different, but the same methodology can be applied in both cases. For thesurface-mounted cube, three groups of flow structures are found. First groupis the mean flow and then two kinds of perturbations around the mean flow.The first perturbation is at the edge of the wake, relating to the shear layerbetween the free stream and the disturbed flow. The second perturbation isinside the wake and is the convection of vortices. These groups would then betypical of the separation bubble that exists in the wake of the cube. For theATM the main flow topology consists of two counter rotating vortices. Thiscan be seen in the decomposed modes, which, except for the mean flow, almostonly contain flow structures relating to these vortices. / QC 20100518 / Gröna Tåget

The aim of the thesis is to devise a methodology which is capable of reliable evaluation of road vehicle’s crosswind sensitivity. The work consists of writing the mathematical model of a vehicle which includes aerodynamic loads and conducting a validation by means of technical experiment as defined by ISO 12021. A sensitivity analysis describing the influence of individual inputs on evaluation criteria of vehicle’s crosswind sensitivity is performed using the model, thereby establishing the overall model error caused by possible inaccuracies of input parameters. At the end, the relationship between discrete pressures on the surface of the vehicle in several aerodynamic configurations and the properties representing the vehicle’s motion is presented.

Introduction : En cyclisme, la résistance aérodynamique est la force principale qui s’oppose à son déplacement et devient non négligeable dès 10 m/s. La surface de traînée (CDAP) constitue un facteur important de cette dernière et varie en fonction de la surface frontale (AP). Ce projet de recherche veut évaluer la fiabilité et la validité d’une méthode de mesure accessible de la surface frontale (AP). Méthode : 14 cyclistes ont été sélectionnés : 31  14 ans; 177,21  6,73 cm; 74,83  8,97 kg et divisés en deux groupes, amateurs et experts. La méthode par digitalisation est utilisée pour l’évaluation de Ap et une méthode par régression linéaire est utilisée pour CDAP en utilisant le logiciel MATLAB_R2019. Résultats : la surface frontale obtenue est AP = P1, 0,433  0,05 m2; P2, 0,413  0,04 m2; P3, 0,387  0,05 m2 avec un ICC intra ; 0,998, et un ICC inter ; 0,523 (p < 0,05). Pour CDAP = P1, 0,414  0,07 m2; P2, 0,435  0,14 m2; P3, 0,399  0,12 m2 avec une variation de R = 0,10 à 0,34. Conclusion : la mesure de AP avec une méthode simple est valide et fiable, mais la précision varie selon l’expertise de l’opérateur. La faible corrélation entre AP et CDAP montre que AP ne devrait pas être la seule variable à laquelle nous pouvons nous fier pour améliorer CDAP. L’évaluation de la surface frontale projetée par digitalisation permettrait d’améliorer la performance aérodynamique en cyclisme. D’autres recherches d’optimisation des outils d’évaluation aérodynamique permettraient d’obtenir des résultats plus précis. / Introduction : In the cycling world, aerodynamic resistance is the principal force that oppose a moving cyclist and is most important at 10 m/s. Drag area (CDAP) is an important factor of this force and depends of the frontal area (AP). This project wants to evaluate the reliability and the validity of an accessible method of measurements of the frontal area (AP). Method : 14 cyclists were selected : 31  14 years; 177,21  6,73 cm; 74,83  8, 97 kg and divided in two groupes, amateurs et experts. The digital method is used for the evaluation of Ap and a linear regression is used with MATLAB_R2019 for finding CDAP. Résults : the obtained frontal area AP = P1, 0,433  0,05 m2; P2, 0,413  0,04 m2; P3, 0,387  0,05 m2 with an ICC intra-operator; 0,998, and an ICC inter-operator; 0,523 (p < 0,05). Pour CDAP = P1, 0,414  0,07 m2; P2, 0,435  0,14 m2; P3, 0,399  0,12 m2 with a correlation variation of R = 0,10 à 0, 34. Conclusion : Measuring Ap with a simple method is reliable and present good validity, but the precision will vary with the expertise of the operator. The weak correlation between AP and CDAP show that AP shouldn’t be the only variable that we have to rely to reduce CDAP. In the end, the evaluation of frontal area with a simple digital method could increase aerodynamic performance in cyclist. Although, further research on optimising aerodynamic evaluation tools would allow to obtain results that are more precise.

Asymmetric bending is explored as a means of inducing bend-twist coupling in an isotropic, fixed-wing airfoil. An analytical model describing the bend-twist coupling behavior of a constant-section airfoil undergoing steady wind loading is derived from Euler-Bernoulli beam theory, and evaluated over a range of structural and material stiffness. Finite element analysis is carried out in the ANSYS Parametric Design Language environment for an asymmetric, two-dimensional beam. Three-dimensional finite element analysis is carried out for two candidate blade models created in Pro/Engineer based on the NACA 64618 airfoil. Deformation results for the two- and three-dimensional finite element models are compared with analytical solutions. Results of this investigation highlight the dependency between the cross-sectional properties of a spar support and its tendency to exhibit twist-coupling under transverse loading.