<p>Denna högskoleavhandling beskriver konstruktionen av ett system vars funktion är att PID-reglera ett linjärställdon kopplad till venturi. Syftet har varit att få fram en reglering på venturin så att förutsättningarna förblir desamma vid mätning av olika temperaturer och lufttryck i en testrigg. Denna testrigg används för att utveckla produkten Varivent som används för att uppfylla högre miljökrav på förbränningsmotorer.</p><p>I arbetet beskriver jag de olika krav som funnits för att bygga det nya systemet, dessa var ingångar, utgångar, mikroprocessor, reglering,</p><p>kommunikation samt övriga krav. Jag diskuterar de svårigheter och möjligheter som är förknippade med kraven och tar även upp de komponenter jag använt samt deras egenskaper. Det svåraste momentet har varit PID-regulatorn som både varit en viktig och en svårlöslig del i konstruktionen av systemet. Slutligen diskuterar jag resultatet där jag, i en analys, kan se att jag kunde underlättat för mig själv med andra angreppsvinklar men att det slutliga resultatet ändå blivit mycket tillfredsställande.</p> / <p>This bachelor thesis describes the design of a unit the function of which is to regulate, using PID controls, a linear mechanical adjusting screw coupled to a variable venturi flow system. The design criteria has been to create, in a test rig, a venturi control system that gives an output that is not affected by changes in either air temperature or pressure. The test rig is used for the development of Varivent, a product used to reduce the environmental impact of the internal combustion engine. In my thesis work I describe the various and necessary elements of the project. These can be termed inputs, outputs, microprocessors, regulators and communicators. I discuss the difficulties and possibilities associated with the design criteria and mention the components used and their different attributes. The most challenging part of the project has been the design of the PID regulator, which, whilst being the heart of the system, has also been the most difficult part of the system to design. Finally I discuss my results where, in an analysis, I see that I could have made things easier for myself had I approached the problems in other ways but that the final result was, despite this, very satisfactory.</p>

Recently, the portfolio of compounds approved for inhalation therapy has expanded rapidly for lung disease therapies. The rationale for this delivery approach includes a more targeted and localized delivery to the diseased site with reduced systemic exposure, potentially leading to decreased adverse side effects. We have proposed that brittle matrix powders prepared by thin film freezing (TFF) are a suitable platform for pulmonary drug delivery which can achieve high lung concentrations while limit the corresponding systemic levels associated with toxicity, and enhanced physicochemical and aerodynamic properties can be obtained by varying TFF processing parameters. In Chapter 2, the in vitro and in vivo performance of an amorphous formulation prepared by TFF and a crystalline micronized formulation produced by milling was compared for Tacrolimus (TAC). TFF processed matrix powders was capable of achieving deep lung delivery due to its low density, highly porous and brittle characteristics. When emitted from a Miat® monodose inhaler, TFF processed TAC formulations exhibited a fine particle fraction (FPF) of 83.3% and a mass median aerodynamic diameter (MMAD) of 2.26 µm. Single dose 24-h pharmacokinetic studies in rats demonstrated that the TAC formulation prepared by TFF exhibited higher pulmonary bioavailability with a prolonged retention time in the lung, possibly due to decreased clearance (e.g., macrophage phagocytosis), compared to the micronized TAC formulation. Additionally, TFF formulation generated a lower systemic TAC concentration with smaller variability than the micronized formulation following inhalation, potentially leading to reduced side effects related to the drug in systemic circulation. Chapter 3 investigated the impact of processing parameters in the TFF process on the physicochemical and aerodynamic properties of the resulting formulations. All of these enhanced powder properties resulted from higher freezing rate contributed to a better aerodynamic performance of the obtaining formulations. Moreover, a decreasing trend of FPF was observed for these TFF powders when the initial solid concentrations increased. The variation of the freezing rate and initial solid loading in the TFF process enabled the production of formulations with enhanced physicochemical properties and improved aerodynamic performance. / text

With the advent of steerable, ram air parafoil canopies, aerial payload delivery has become a viable alternative for situations involving remote or undeveloped areas, hostile environments, or otherwise inaccessible locations. Autonomously guided systems utilizing such steerable, ram air canopies are typically controlled by symmetric and asymmetric deflection of the canopy trailing edge. Although these systems have demonstrated substantial improvement in landing accuracy over similarly sized unguided systems, their low number of available control channels and limited ability to alter vehicle glide slope during flight makes them highly susceptible to atmospheric gusts and other unknown conditions near the target area. This research aims to improve landing accuracy in such adverse conditions by replacing the standard trailing edge deflection control mechanism in favor of upper surface canopy spoilers. These spoilers operate by opening several spanwise slits in the upper surface of the parafoil canopy thus forming a virtual spoiler from the stream of expelled pressurized air. In particular, estimation of steady-state vehicle flight characteristics in response to different symmetric and asymmetric spoiler openings was determined for two different small-scale test vehicles. Additionally, improvements in autonomous landing accuracy using upper surface spoilers in a combined lateral and longitudinal control scheme was investigated computationally using a high fidelity, 6-DOF dynamic model of the test vehicle and further validated in actual flight experiments with good results. Lastly, a novel in-canopy bleed air actuation system suitable for large-scale parafoil aircraft was designed, fabricated, and flight-tested. The in-canopy system consists of several small, specifically designed wireless winch actuators mounted entirely inside the parafoil canopy. Each in-canopy actuator is capable of opening one or more upper surface canopy spoilers via a unique internal rigging structure. This system demonstrates not only the applicability of bleed air spoiler control for large-scale autonomous parafoil and payload aircraft, but also provides the potential for significant savings in size, weight, and cost of the required actuation hardware for currently fielded systems.

Pressurized metered dose inhalers (pMDIs) are widely utilized to manage diseases of the lungs, such as asthma and chronic obstructive pulmonary disease. They can be formulated such that the drug and/or nonvolatile excipients are dissolved or dispersed in the formulation, rendering a solution or suspension formulation, respectively. While the formulation process for solution pMDIs is well defined, the formulation process of pMDIs with any type of suspended entity can be lengthy and empirical. The use of suspended drug or the addition of a second drug or excipient in a suspension pMDI formulation may non-linearly impact the product performance of the drug of interest in the formulation; this requires iterative testing of a series of pMDIs in order to identify a formulation with the most potential for success. One of the primary attributes used to characterize the product performance and quality control of inhaled medications is the residual aerodynamic particle size distribution (APSD) of the aerosolized drug. Along with clinical factors, formulation and device parameters have a significant impact on APSD. In this study, a computational model was developed using the principles of statistics and physical chemistry to predict the residual APSD generated by suspension pMDIs based on formulation, device, and raw drug or excipient substance considerations. The formulations modeled and experimentally evaluated consist of a suspended drug or excipient with/without a dissolved drug or excipient in a cosolvent-propellant system. The in silico model enables modeling a process that is difficult to delineate experimentally and contributes to understanding the link between pMDI formulation and device to product performance. The ability to identify and understand the variables that affect atomization and/or aerosol disposition , such as initial droplet size, suspended micronized drug or excipient size, and drug or excipient concentration, facilitates defining the design space for suspension pMDIs during development and improves recognizing the sensitive of the APSD is on each hardware and formulation variable. This model can later be applied to limit batch-to-batch variation in the manufacturing process and selecting plausible suspension pMDI formulations with quality design as the end goal.

Denna högskoleavhandling beskriver konstruktionen av ett system vars funktion är att PID-reglera ett linjärställdon kopplad till venturi. Syftet har varit att få fram en reglering på venturin så att förutsättningarna förblir desamma vid mätning av olika temperaturer och lufttryck i en testrigg. Denna testrigg används för att utveckla produkten Varivent som används för att uppfylla högre miljökrav på förbränningsmotorer. I arbetet beskriver jag de olika krav som funnits för att bygga det nya systemet, dessa var ingångar, utgångar, mikroprocessor, reglering, kommunikation samt övriga krav. Jag diskuterar de svårigheter och möjligheter som är förknippade med kraven och tar även upp de komponenter jag använt samt deras egenskaper. Det svåraste momentet har varit PID-regulatorn som både varit en viktig och en svårlöslig del i konstruktionen av systemet. Slutligen diskuterar jag resultatet där jag, i en analys, kan se att jag kunde underlättat för mig själv med andra angreppsvinklar men att det slutliga resultatet ändå blivit mycket tillfredsställande. / This bachelor thesis describes the design of a unit the function of which is to regulate, using PID controls, a linear mechanical adjusting screw coupled to a variable venturi flow system. The design criteria has been to create, in a test rig, a venturi control system that gives an output that is not affected by changes in either air temperature or pressure. The test rig is used for the development of Varivent, a product used to reduce the environmental impact of the internal combustion engine. In my thesis work I describe the various and necessary elements of the project. These can be termed inputs, outputs, microprocessors, regulators and communicators. I discuss the difficulties and possibilities associated with the design criteria and mention the components used and their different attributes. The most challenging part of the project has been the design of the PID regulator, which, whilst being the heart of the system, has also been the most difficult part of the system to design. Finally I discuss my results where, in an analysis, I see that I could have made things easier for myself had I approached the problems in other ways but that the final result was, despite this, very satisfactory.

A set of techniques is developed that allows the incorporation of flight dynamics metrics as an additional discipline in a high-fidelity aerodynamic optimization. Specifically, techniques for including static stability constraints and handling qualities constraints in a high-fidelity aerodynamic optimization are demonstrated. These constraints are developed from stability derivative information calculated using high-fidelity computational fluid dynamics (CFD). Two techniques are explored for computing the stability derivatives from CFD. One technique uses an automatic differentiation adjoint technique (ADjoint) to efficiently and accurately compute a full set of static and dynamic stability derivatives from a single steady solution. The other technique uses a linear regression method to compute the stability derivatives from a quasi-unsteady time-spectral CFD solution, allowing for the computation of static, dynamic and transient stability derivatives. Based on the characteristics of the two methods, the time-spectral technique is selected for further development, incorporated into an optimization framework, and used to conduct stability-constrained aerodynamic optimization. This stability-constrained optimization framework is then used to conduct an optimization study of a flying wing configuration. This study shows that stability constraints have a significant impact on the optimal design of flying wings and that, while static stability constraints can often be satisfied by modifying the airfoil profiles of the wing, dynamic stability constraints can require a significant change in the planform of the aircraft in order for the constraints to be satisfied.

Šiuolaikinių ilgųjų kabamųjų ir vantinių tiltų konstrukcijos santykinai lengvos, neatsparios kinematiniams poslinkiams, kuriuos gali sukelti vėjo poveikis. Konstrukcijos pastovumas vėjo apkrovai susijęs su jos aptakumu, skerspjūvio forma, standžiu. Darbe nagrinėti pagrindiniai aerodinaminiai reiškiniai, jų įvertinimas taikant LST_EN_1991-1-4_2007 (lt) metodiką. Išanalizuotos programinio paketo COSMOSFloWorks galimybes vertinant vėjo poveikį. Atlikta aerodinamio plazdėjimo ir periodinių sūkurių susidarymo priklausomybės nuo skerspjūvio aptakumo parametrų analizė. Atliktas vantiniam tiltui, stovėsiančiam Klaipėdoje vėjo poveikio įvertinimas. Išanalizuotos vėjo poveikio, bei jo sukeliamų vibracijų konstrukcijose slopinimo sistemos. Darbą sudaro septynios dalys: įvadas, vėjo poveikio analizė, vėjo poveikio vertinimas, realių konstrukcijų tyrimas vėjo poveikiams, vėjo poveikio stabilizavimas, išvados ir rezultatai, literatūros sąrašas. Darbo apimtis – 94 puslapiai, 108 paveikslų, 9 lentelių, 41 bibliografiniai šaltiniai. / Modern long suspension and cable-stayed bridge constructions are relatively light and not resistant for kinematic displacements, which can make a result of wind effect. Stability of a construction against the impact of wind is related to its siffness, cross-section shape. The paper analyzes basic aerodynamic phenomenon’s and their estimation according to LST_EN_1991-1-4_2007 (lt) methodology. The capabilities of a software package COSMOSFloWorks were investigated against wind impact. Relationship between aerodynamic flutter and periodic vortex-sheeding with respect to flow around cross-section estimation. An estimation of wind impact on a cable-stayed bridge was performed. The bridge is planned to be built in Klaipeda city. Damping systems for wind impact and wind inflicted vibrations is analyzed in the paper as well. A periodic vortex-sheeding damping system for the particular bridge is proposed in the paper. The paper is composed of seven parts: introduction, wind impact analysis, wind impact evaluation, investigation of real constructions resistance to wind impact, stabilisation of wind impact, conclusions and results, list of references. The paper is 94 pages long, has 108 illustrations, 9 tables and 41 items in the list of references.

No description available.

This thesis addresses the problem of designing and evaluating passive satellite attitude control systems for small satellites. Passive stabilization techniques such as Gravity Gradient stabilization, Passive Magnetic Stabilization, and Aerodynamic stabilization in Low Earth Orbit utilize the geometric and magnetic design of a satellite and the orbit properties to passively provide attitude stabilization and basic pointing. The design of such stabilization systems can be done using a high fidelity simulation of the satellite and the environmental effects in the orbit under consideration to study the on-orbit behavior and the effectiveness of the stability system in overcoming the disturbance torques. The Orbit Propagator described in this thesis is developed to include models for orbit parameters, Gravity Gradient torque, Aerodynamic Torque, Magnetic Torque, and Magnetic Hysteresis Material for angular rate damping. Aerodynamic stabilization of a three-unit CubeSat with deployable side panels in a “shuttlecock” design is studied in detail. Finally, the Passive Magnetic Stabilization system of KySat-1, a one-unit CubeSat, is also described in detail and the simulation results are shown.

The accuracy of existing methods for estimating the drag based on experimental flow field measurements were assessed for two-dimensional bodies. The effects of control volume boundary placement and inherent simplifying assumptions were also investigated. Wind tunnel experiments were performed on a circular cylinder operating at a Reynolds number of 8,000 and 20,000, and on a NACA 0018 airfoil operating at a chord Reynolds number of 100,000 for three angles of attack (α), specifically, 5◦, 10◦, and 15◦. The circular cylinder experiments fall within the the shear layer transition flow regime. Airfoil investigations span both types of flow development common to low Reynolds number airfoil operation. For α = 5◦ and 10◦, a separation bubble forms on the upper surface of the airfoil, while, for α = 15◦, the flow separates without reattaching, resulting in a stalled airfoil. Wake velocity and pressure measurements were performed at several downstream locations to investigate the impact of control volume boundary placement. Wake profiles were measured between 3 and 40 diameters downstream from the circular cylinder axis and between 1 and 4.5 chord lengths from the trailing edge of the airfoil. In addition to wake profiles, the outer flow velocity variation was quantified to investigate the appropriate location to measure freestream flow characteristics in a test section with streamwise-varying outer flow conditions. The results show that drag estimates are strongly dependent on the streamwise position of the measured wake profile for all methods investigated. Drag estimates improved, and streamwise variation decreased, with increasing streamwise position of the flow measurements. For the pressure based method examined, wake measurements should be taken at least 10 times the projected model height downstream of the model. In the case of the circular cylinder, this is equivalent to 10 diameters and, for the airfoil investigated, it is approximately 1 chord length from the trailing edge. For the methods relying on velocity measurements, acceptable estimates of drag were possible when based on measurements taken at least 30 projected heights downstream, i.e., 30 diameters for the circular cylinder and 3 chord lengths for the airfoil model investigated. The findings highlight the importance of providing a detailed description of the methodology and experimental implementation for drag estimates based on flow field measurements. Finally the study offers guidelines for implementing momentum integral based drag calculations in future investigations.