Locomotion is central to the survival of many animal species; however large variation in performance, for example in speed or endurance, exists between individuals within a species. Using the bumblebee species, Bombus impatiens, I studied the extent of the variation in several flight performance traits and how they are associated. I first addressed how bumblebee workers vary in foraging effort and observed that only around half of the monitored individuals underwent foraging activity. Additionally, significant variation in metabolic rate between foragers and non-foragers was uncovered. I further investigated if such variation could be associated with flight performance capacity, such as an individual’s ability to carry a load, their flight speed and distance traveled, their wing morphology and kinematics, and their flight metabolic rate. These traits are commonly measured to characterize flight capacity in insects, however the links between them have yet to be investigated. Links between morphology, wing kinematics and peak metabolic rate previously uncovered in the literature were observed in my analysis, although variation in their scaling with body mass was detected. Vertical force scaled isometrically with body mass but was not related to it when expressed in on a mass specific basis (VF m-1g-1, where m is gravitation acceleration). In regard to forward flight speed, body mass does have an affect, however it alone does not have a great degree of explanatory power and other factors such as morphology and wing kinematics are likely to play a greater part in its determination. Finally, maximum flight speed had a significant relationship with total flight time. Together, these results demonstrate that some links do exist between flight performance traits, however links are not present between all traits and certain flight performance traits should be treated as independent of each other.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Understanding the impact of environmental factors on locomotor performance and flight energetics is of fundamental importance to understanding evolution and ecology. Increased performance that leads to increased dispersal ability can result in increased migration distance to reach optimal habitats, increased gene flow between populations and an overall contribution to the survival of individuals as well as the structuring of species‟ geographic range sizes. The temperature-dependent nature of insects, in conjunction with predicted climate change and shifting optimal climatic ranges, could have important ecological and economic consequences such as increased invasion by alien and pest species. In this study, the influence of thermal history on temperature-dependent flight performance was investigated in a notorious invasive agricultural pest, Ceratitis capitata (Diptera: Tephritidae). Flies were exposed to one of four developmental acclimation temperatures (Tacc: 15, 20, 25, 30°C) during their pupal stage and tested at random at either of those temperatures (Ttest) as adults in a full-factorial experimental design. Major factors influencing flight performance included sex, body mass, Ttest and the interaction between Ttest and Tacc. Performance increased with increasing Ttest across all acclimation groups, e.g. at 15°C only 10% of all flies had successful flight, whereas at 30°C the success rate was 76.5%. Even though Tacc alone did not affect flight performance, it did have an effect in combination with Ttest. The negative interaction term Ttest x Tacc, in combination with a multiple comparison between Tacc groups at each Ttest, indicated that flies acclimated to 15°C and 20°C performed better than those acclimated to 25°C and 30°C when tested at cold temperatures. This provides partial support for the "colder is better‟ hypothesis. To explain these results, several key, flight-related traits were examined to determine if Tacc influenced flight performance as a consequence of changes in body or wing morphology, whole-animal metabolic rate or cytochrome c oxidase (CCO) activity. Although significant effects of Tacc could be detected in several of the traits examined, with emphasis on sex-related differences, increased flight performance could not be explained solely on the basis of changes in any one of these traits. To illustrate the potential applied value of this study, the main flight performance outcomes were also coupled with a degree-day (thermal development) model to determine if knowledge of flight ability could improve predicted population dynamics. The results and insights obtained from this study are broadly applicable to a variety of insect species and demonstrate that, by recognising the impact of environmental factors on locomotor performance and flight energetics, an increased understanding of the functioning, biology and evolution of flight-capable arthropods can be obtained. / AFRIKAANSE OPSOMMING: Groter begrip van die impak van omgewingsfaktore op bewegingsprestasie en vlug-energetika is van fundamentele belang vir die verstaan van evolusie en ekologie. Verhoogde bewegingsprestasie wat lei tot verbeterde verspreidingsvermoë kan 'n toename in migrasieafstand om optimale habitat te bereik, verhoogde genevloei tussen populasies en ʼn algehele bydrae tot die oorlewing van individue sowel as die strukturering van spesies se geografiese gebiedsgroottes tot gevolg hê. Die temperatuurafhanklike aard van insekte, tesame met voorspelde klimaatsverandering en die verskuiwing van optimale klimaatsones, kan belangrike ekologiese en ekonomiese gevolge, soos verhoogde indringing deur uitheemse en pes-spesies, inhou. Die invloed van termiese geskiedenis op die temperatuurafhanklike vlugprestasie van 'n berugte indringer-landboupes, Ceratitis capitata (Diptera: Tephritidae), word in hierdie studie ondersoek. Vlieë is blootgestel aan een van vier akklimasie-temperature (Tacc: 15, 20, 25, 30°C) tydens hul papiestadium en is op ewekansige wyse in 'n vol-faktoriale eksperimentele ontwerp by een van dieselfde toetstemperature (Ttest) as volwassenes getoets. Belangrike faktore wat vlugprestasie beïnvloed het, sluit geslag, liggaamsmassa, Ttest en die interaksie tussen Ttest en Tacc in. Prestasie het verbeter met toenemende Ttest oor al die akklimasiegroepe, bv. by 15°C het net 10% van alle vlieë suksesvol gevlieg, terwyl die sukseskoers by 30°C, 76,5% was. Selfs al het Tacc alleen nie die vlugprestasie beïnvloed nie, het dit 'n effek in kombinasie met Ttest gehad. Die negatiewe interaksie term Ttest x Tacc, in samewerking met 'n meervoudige vergelyking tussen Tacc groepe by elke Ttest, het aangedui dat vlieë wat by 15°C en 20°C geakkimeer was, beter presteer het as dié wat by 25°C en 30°C geakklimeer was wanneer hulle by koue temperature getoets was. Dit bied gedeeltelike ondersteuning vir die "kouer is beter" hipotese. Om hierdie resultate te verklaar, is 'n paar sleutel vlugverwante eienskappe ondersoek om te bepaal of Tacc vlugprestasie a.g.v. veranderinge in die liggaam- of vlerkmorfologie, die hele-dier metaboliesetempo of sitochroom-c oksidase (CCO) aktiwiteit beïnvloed. Alhoewel beduidende effekte van Tacc op verskeie van hierdie eienskappe, veral wat geslagsverwante verskille betref, opgemerk is, kan verhoogde vlugprestasie nie uitsluitlik op grond van veranderinge in enige een van die eienskappe verduidelik word nie. Om die potensiële toepassingswaarde van hierdie studie te illustreer, is die hoof vlugprestasie uitkomste gekoppel aan 'n “degree-day” (termiese ontwikkeling)-model om te bepaal of kennis van vlugvermoë voorspellings van bevolkingsdinamika kan verbeter. Hierdie studie se resultate en insigte is oor die algemeen van toepassing op 'n verskeidenheid insek-spesies en toon dat erkenning van die invloed van omgewingsfaktore op bewegingsprestasie en vlug-energetika kan lei tot groter begrip van die funksionering, biologie en evolusie van geleedpotiges.

Bumblebees are experiencing declines and range contractions globally that are, in some cases, independent of anthropogenic pesticide- or land-use change, leaving rising global temperatures as the primary driver of such loses. With ambient temperature (Ta) and thermal limitations being a crucial component in these observed declines, I sought to determine the physiological limitations that high Ta imposes on both individuals and colonies of a temperate bumblebee species, Bombus impatiens. Through Chapter 2, I first established the upper thermal tolerance (CTmax) of the species, testing both adults and larvae to determine which of these colony castes are most thermally sensitive to heat. Collective thermoregulation at the colony-level is then important to ensure that the most heat sensitive individuals are protected from changes in optimal nest temperature (Tn). I thus identified the energetic costs associated with colonial thermoregulation and whether large colonies could successfully achieve thermal homeostasis under various Ta. Chronic bouts of heat stress are also of concern as colonies invest time and energy into thermoregulation, especially given that heatwave events are becoming more frequent. In Chapter 3, I examined whether there exists a trade-off between thermoregulation and foraging effort for colonies under chronic heat stress and how various measures of colony success are impacted. Finally, foraging requires individuals to employ flight for the procurement of resources. In Chapter 4, I investigated if the temperate adaptation of an insulative pile layer would hinder flight performance under high Ta by assessing the metabolic rates of adult castes during flight. I found that larvae were more thermally sensitive compared to bumblebee adults, which emphasizes the importance of colonial thermoregulation – a task successful at low Ta. Under heat stress, however, Tn could not be maintained despite elevated energetic investments (Chapter 2). These findings suggest that Ta which exceeds optimal Tn may pose significant challenges to colonies; not only energetically but also to the health of thermally sensitive larvae within. A trade-off between thermoregulation and foraging effort did not emerge for colonies experiencing chronic exposure to high Ta. Instead, only high incidences of thermoregulation were observed which failed to prevent increases in Tn. Furthermore, a greater number of individuals were found to abandon the colony at high Ta, and fewer offspring were produced (Chapter 3). Here, findings suggest that chronic high Ta may pose the greatest risk to the production of thermally sensitive offspring by way of reduced worker population and failed thermoregulation. Finally, the metabolic output during flight at high Ta was not found to be affected by an insulative layer of pile (Chapter 4), indicating that either pile may play a role in limiting other measures of flight performance at high Ta, or that alternate physiological mechanisms may be responsible instead. Together the findings from this thesis broaden the understanding of how a temperate species of bumblebee responds physiologically to high Ta both at the individual and colonial level, providing further evidence on thermal limitations in a changing climate.

The thesis deals with the issue of replacement of the Rotax 912 ULS engine with the Rotax 915 iSc3 B engine and its impact on flight performance, characteristics and airframe loads of the WT 9 Dynamic. For accomplish better maneuverability tail surfaces are enlarged. Both versions of airplane with different engines and tails surfaces are quantified with respect to airframe loads and flight characteristics. The output of the diploma thesis can be used for strength design of airplane structure and stress tests of the new modification of the WT 9 Dynamic aircraft.

The aim of this diploma thesis is to analyse flight performance of airplane VUT-081 Kondor. The first part focuses on determination and estimation of aerodynamic characteristics of the airplane. Based on this data flight performance was calculated and evaluated according to CS-ELSA. The last part is dedicated to comparison of flight performance of VUT-081 Kondor with other similar airplanes.

No description available.

This study focuses on the external configuration design of a tactical missile based on maximizing flight range while minimizing the radar signature which is a crucial performance parameter for survivability. It is known that shaping of a missile according to aerodynamic performance may have significant negative effects on the radar cross section. Thus, the impact of the geometry changes on the aerodynamic performance and the radar cross section is investigated. Suggorage models for the flight range, control effectiveness and the radar cross section (RCS) at an X band frequency are established by employing Genetic Algorithm. Accuracies of surrogate models are discussed in terms of statistical parameters. Seventeen geometrical parameters are considered as the design variables. Optimum combinations for the design variables are sought such that flight range is maximized while the radar cross section is minimized. The multi objective optimization problem is solved by imposing the static stability margin as a hard nonlinear constraint. Weighted sum approach is utilized to compare results with known missile configurations. Weights for flight range and Radar Cross Section are varied to obtain Pareto optimal solutions.

This master‘s thesis is focused on the design of four-seat metal aircraft with low take-off weight in accordance with CS-23. Main dimensions of aircraft are designed, weight analysis, aerodynamic characteristics and flight performance are calculated in this thesis. In conclusion, the estimated costs of development and production are determined.

The main area of emphasis in this study is to investigate the methods and technology for aerodynamic configuration sizing of missiles and to develop a software platform in MATLAB&reg / environment as a design tool which has an ability of optimizing the external configuration of missiles for a set of flight requirements specified by the user through a graphical user interface. A genetic algorithm based optimization tool is prepared by MATLAB is expected to help the designer to find out the best external geometry candidates in the conceptual design stage. Missile DATCOM software package is employed to predict the aerodynamic coefficients needed in finding the performance merits of a missile for each external geometry candidate by integrating its dynamic equations of motion. Numerous external geometry candidates are rapidly eliminated according to objectives and constraints specified by designers, which provide necessary information in preliminary design. In this elimination, the external geometry candidates are graded according to their flight performances in order to discover an optimum solution. In the conceptual design, the most important performance objectives related to the external geometry of a missile are range, speed, maneuverability, and control effectiveness. These objectives are directly related to the equations of motion of the missile, concluding that the speed and flight range are related to the total mass and the drag-to-lift ratio acting on missile. Also, maneuverability depends on the normal force acting on missile body and mass whereas the control effectiveness is affected by pitching moment and mass moment of inertia of missile. All of the flight performance data are obtained by running a two degree-of-freedom simulation. In order to solve the resulting multi-objective optimization problem with a set of constraint of linear and nonlinear nature and in equality and inequality forms, genetic-algorithm-based methods are applied. Hybrid encoding methods in which the integer configuration variables (i.e., nose shape and control type) and real-valued geometrical dimension (i.e., diameter, length) parameters are encoded in the same individual chromosome. An external configuration design tool (EXCON) is developed as a synthesis and external sizing tool for the subsonic cruise missiles. A graphical user interface (GUI), a flight simulator and optimization modules are embedded into the tool. A numerical example, the re-configuration problem of an anti-ship cruise missile Harpoon, is presented to demonstrate the accuracy and feasibility of the conceptual design tool. The optimum external geometries found for different penalty weights of penalty terms in the cost function are compared according to their constraint violations and launch mass values. By means of using EXCON, the launch mass original baseline Harpoon is reduced by approximately 30% without deteriorating the other flight performance characteristics of the original Harpoon.

The primary goal for the conceptual design phase of a generic air-to-ground missile is to reach an optimal external configuration which satisfies the flight performance requirements such as flight range and time, launch mass, stability, control effectiveness as well as geometric constraints imposed by the designer. This activity is quite laborious and requires the examination and selection among huge numbers of design alternatives. This thesis is mainly focused on multi objective optimization techniques for an air to-ground missile design by using heuristics methods namely as Non Dominated Sorting Genetic Algorithm and Multiple Cooling Multi Objective Simulated Annealing Algorithm. Futhermore, a new hybrid algorithm is also introduced using Simulated Annealing cascaded with the Genetic Algorithm in which the optimized solutions are passed to the Genetic Algorithm as the intial population. A trade off study is conducted for the three optimization algorithm alternatives in terms of accuracy and quality metrics of the optimized Pareto fronts.