In 21 century finned surfaces are used in almost all condensers to enhance their heat transfer capabilities. A lot of different models are presented in the literature: on horizontal and vertical finned tubes, inside finned tubes. The validation method of the theoretical models is based on comparison between measurement of average heat transfer coefficient and one calculated by the model. But in this case it is impossible to validate all approaches made in the theory. The presented work aims to understand the real relation between assumptions made in the theory and flow of the condensate film along a fin. Therefore a comprehensive investigation of the film condensation phenomena on curvilinear surfaces has been done. This investigation has been done in the framework of the preparation of “SAFIR” and “EMERALD” space experiments aboard International Space Station. A special attention has been given to clarify some technical and technological problems that could eventually have a positive feedback for industrial applications. The model of the fin shape optimization has been developed. It takes into account surface tension forces and finite heat conductivity of the fin material. Developed model allows to significantly increase the condensate outflow as compared with the case of the optimal isothermal fin shape at the finite heat transfer conductivity. Enhancement coefficient increases with fin heat conductivity decreasing. The experimental and theoretical investigation of film condensation on a disk-shaped fin has been done under groun condition. 3D condensation model at different gravity levels has been developed. This model allows to reveal the area of dominant influence of surface tension forces. First prototype of experimental cell for the space experiments has been developed and tested. The temperature distribution along the curvilinear fin surface has been measured. The measurements of the film thickness at the fin top shows that the film thickness does not equal to zero as was assumed in some previous theoretical models. Developed model is in a good agreement with experimental results. In the ground set-up the measurement techniques as in future space experiments were realized: local temperature measurement of the fin surface, measurement of non-condensable gas mole fraction, optical system for local film thickness measurement and system of average heat transfer coefficient measurement. Experimental results approve the usefulness of these systems. Optical system based on schlieren technique for film surface deformation has been investigated and developed. This system was used for the investigation of shear driven liquid film on the mirror like substrate under microgravity condition. The microgravity condition was simulated during ESA Parabolic Flight Campaign of October-November 2009. The experimental results show the high capabilities of this system. In the framework of the space experiments preparation the analysis of appropriate liquid has been done. Three candidates have been compared: Water, Ethyl alcohol and FC-72. Third liquid has been chosen as applicable liquid for the “SAFIR” and “EMERALD” experiments. The optimal fin shapes and film thickness distribution have been calculated for the working liquid. Using obtained results requirements for space experiments have been prepared.

Plasma turbulence associated with the creation of an artificial dust layer in the earth's ionosphere is investigated. The Charged Aerosol Release Experiment (CARE) aims to understand the mechanisms for enhanced radar scatter from plasma irregularities embedded in dusty plasmas in space. Plasma irregularities embedded in a artificial dusty plasma in space may shed light on understanding the mechanism for enhanced radar scatter in Noctilucent Clouds (NLCs) and Polar Mesospheric Summer Echoes (PMSEs) in the earth's mesosphere. Artificially created, charged-particulate layers also have strong impact on radar scatter as well as radio signal propagation in communication and surveillance systems. The sounding rocket experiment was designed to develop theories of radar scatter from artificially created plasma turbulence in charged dust particle environment. Understanding plasma irregularities embedded in a artificial dusty plasma in space will also contribute to addressing possible effects of combustion products in rocket/space shuttle exhaust in the ionosphere. In dusty space plasmas, plasma irregularities and instabilities can be generated during active dust aerosol release experiments. Small scale irregularities (several tens of centimeter to meters) and low frequency waves (in the ion/dust scale time in the order of second) are studied in this work, which can be measured by High Frequency (HF), Very High Frequency (VHF) and Ultra High Frequency (UHF) radars. The existence of dust aerosol particles makes computational modeling of plasma irregularities extremely challenging not only because of multiple spatial and temporal scale issue but also due to complexity of dust aerosol particles. This work will provide theoretical and computational models to study plasma irregularities driven by dust aerosol release for the purpose of designing future experiments with combined ground radar, optical and in-situ measurement. In accordance with linear analysis, feasible hybrid computational models are developed to study nonlinear evolution of plasma instabilities in artificially created dusty space plasmas. First of all, the ion acoustic (IA) instability and dust acoustic (DA) instability in homogenous unmagnetized plasmas are investigated by a computational model using a Boltzmann electron assumption. Such acoustic-type instabilities are attributed to the charged dust and ion streaming along the geomagnetic field. Secondly, in a homogenous magnetized dusty plasma, lower-hybrid (LH) streaming instability will be generated by dust streaming perpendicular to the background geomagnetic field. The magnetic field effect on lower-hybrid streaming instabilities is investigated by including the ratio of electron plasma frequency and electron gyro frequency in this model. The instability in weakly magnetized circumstances agree well with that for the ion acoustic (IA) instability by a Boltzmann model. Finally, in an inhomogeneous unmagnetized/magnetized dust boundary layer, possible instabilities will be addressed, including dust acoustic (DA) wave due to flow along the boundary and lower-hybrid (LH) sheared instability due to flow cross the boundary. With applications to active rocket experiments, plasma irregularity features in a linear/nonlinear saturated stage are characterized and predicted. Important parameters of the dust aerosol clouds that impact the evolution of waves will be also discussed for upcoming dust payload generator design. These computational models, with the advantage of following nonlinear wave-particle interaction, could be used for space dusty plasmas as well as laboratory dusty plasmas. / Ph. D.

International Telemetering Conference Proceedings / October 28-31, 1996 / Town and Country Hotel and Convention Center, San Diego, California / This paper reviews the performance requirements that provided the baseline for development of the onboard data system, RF transmission system, and ground segment receiving system of the Midcourse Space Experiment (MSX) spacecraft. The onboard Command and Data Handling (C&DH) System was designed to support the high data outputs of the three imaging sensor systems onboard the spacecraft and the requirement for large volumes of data storage. Because of the high data rates, it was necessary to construct a dedicated X-band ground receiver system at The Johns Hopkins University Applied Physics Laboratory (APL) and implement a tape recorder system for recording and downlinking sensor and spacecraft data. The system uses two onboard tape recorders to provide redundancy and backup capabilities. The storage capability of each tape recorder is 54 gigabits. The MSX C&DH System can record data at 25 Mbps or 5 Mbps. To meet the redundancy requirements of the high-priority experiments, the data can also be recorded in parallel on both tape recorders. To provide longer onboard recording, the data can also be recorded serially on the two recorders. The reproduce (playback) mode is at 25 Mbps. A unique requirement of the C&DH System is to multiplex and commutate the different output rates of the sensors and housekeeping signals into a common data stream for recording. The system also supports 1-Mbps real-time sensor data and 16-kbps real-time housekeeping data transmission to the dedicated ground site and through the U.S. Air Force Satellite Control Network ground stations. The primary ground receiving site for the telemetry is the MSX Tracking System (MTS) at APL. A dedicated 10-m X-band antenna is used to track the satellite during overhead passes and acquire the 25-Mbps telemetry downlinks, along with the 1-Mbps and 16-kbps real-time transmissions. This paper discusses some of the key technology trade-offs that were made in the design of the system to meet requirements for reliability, performance, and development schedule. It also presents some of the lessons learned during development and the impact these lessons will have on development of future systems.

The first European commercial research facility aboard the ISS, Space Applications Services' ICF, provides a platform for standardized plug-and-play experiments called ICE Cubes. The ICE Cubes Service provides engineering and operational support for ICE Cubes missions. In order to facilitate rapid and affordable access to space, a programmatic choice was made to mainly use COTS components in Cube design. As part of a company-internal project to develop a generic ICE Cubes platform for biological experiments, a scientific requirements document was drawn up in cooperation with interested scientists. A decision was made to aim for an experiment size of 2U (200x100x100mm). The main scientific requirements are to accommodate six reaction chambers (referred to as "wells") of standardized size; to control the temperature at well level to remain in the nominal interval of (37 +- 1)C; to accommodate a combined volume of 230ml of fluids; to provide capability to image each of the wells; and to allow for freezing of the biological payload to -80C for return to ground. The development of a prototype design for this platform, dubbed BioCube, is the topic of this thesis. Technical requirements were derived, and a functional breakdown was defined. From this, the system was partitioned into five subsystems: Thermal, Imaging/Avionics, Structure, Software, and the biological Payload. The development of the biological system is considered beyond the scope of this thesis, and the development of the software beyond that required for prototyping is left for a later stage in the design process, as significant heritage exists from previous experiments. Using a rapid prototyping approach, a prototype design for this experiment has been developed. The proposed solution utilizes a (205x104x101)mm outer structure, manufactured from aluminium and closed with two lids on the small faces. Inside, the system is split into a 3D printed avionics compartment and a payload compartment, surrounded by an air gap serving as thermal insulation. The payload compartment structure consists of aluminium, closed on one face with a transparent material through which the samples can be imaged, and provides a sealed interface connector for exchange of power and data. Both the outer structure and the payload compartment are sealed at the interfaces using O-ring seals, providing a combined two levels of biosafety containment to the payload. Manual latches on one of the lids of the outer structure allow it to be opened and the payload compartment to be extracted.The system avionics are based on a Raspberry Pi Zero with USB & Ethernet Hub and Motor Control expansion boards. A 5W silicon heating pad attached to the inside of the payload compartment provides heating, and is controlled using a PWM signal from the motor control board.Two cameras arranged in parallel are used to image wells arranged in two rows, reducing the required motion. One axis motion is implemented using a leadscrew mechanism actuated by a DC motor, driven by the motor control board. Prototyping has been performed on nearly every part of the proposed design. The leadscrew assembly has been successfully tested, and tests on a thermal model have successfully demonstrated binary thermal control achieving the nominal temperature range. Some points regarding the design remain to be defined, and more thorough verification and validation of the design remains to be performed. / La première installation de recherche commerciale européenne à bord de l'ISS, l'ICF de Space Applications Services, fournit une plateforme pour des expériences standardisées prêtes à l'emploi appelées ICE Cubes. Le ICE Cubes Service fournit un soutien technique et opérationnel pour les missions ICE Cubes. Afin de faciliter un accès rapide et abordable à l'espace, un choix programmatique a été fait d'utiliser principalement les composants COTS dans la conception des expériences. Dans le cadre d'un projet interne à l'entreprise visant à développer une plateforme ICE Cubes générique pour les expériences biologiques, un document sur les exigences scientifiques a été rédigé en coopération avec les scientifiques intéressés et il a été décidé de viser une taille d'expérience de 2 U (200x100x100 mm). Les principales exigences scientifiques sont les suivantes : accueillir 6 chambres de réaction ("puits") de la taille des puits d'une plaque à 6 puits ; contrôler la température au niveau des puits pour qu'elle reste dans l'intervalle nominal de (37 +- 1)C ; accueillir un volume combiné de 230ml de fluides ; fournir la capacité d'imager chacun des puits; et permettre la congélation de la charge utile biologique à -80\,$^\circ$C pour le retour au sol. Le développement d'un prototype de plate-forme, baptisé BioCube, est le sujet de cette thèse. Les exigences techniques ont été dérivées, et un découpage fonctionnel a été défini. A partir de là, le système a été divisé en cinq sous-systèmes : Thermique, Imagerie/Avionique, Structure, Logiciel, et la charge utile biologique. Le développement du système biologique est considéré comme hors de portée de cette thèse, et le développement du logiciel au-delà de ce qui est nécessaire pour le prototypage est laissé pour une étape ultérieure dans le processus de conception, car il existe un héritage important des expériences précédentes. En utilisant une approche de prototypage rapide, une conception de prototype pour cette expérience a été développée. La solution proposée utilise une structure extérieure de (205x104x101)mm, fabriquée en aluminium et fermée par deux couvercles sur les petites faces. À l'intérieur, le système est divisé en un compartiment avionique imprimé en 3D et un compartiment de charge utile, entourés d'une lame d'air servant d'isolation thermique. Le compartiment de la charge utile est en aluminium, fermé sur une face par un matériau transparent, à travers lequel les échantillons peuvent être imagés, et fournit un connecteur d'interface scellé pour l'échange d'énergie et de données. La structure extérieure et le compartiment de la charge utile sont scellés aux interfaces à l'aide de joints toriques, offrant ainsi deux niveaux combinés de confinement de biosécurité à la charge utile. Des loquets manuels sur l'un des couvercles de la structure extérieure permettent de l'ouvrir et d'extraire le compartiment de la charge utile.L'avionique du système est basée sur un Raspberry Pi Zero avec des cartes d'extension USB & Ethernet Hub et Motor Control.Un coussin chauffant en silicone de 5W fixé à l'intérieur du compartiment de la charge utile, assure le chauffage et est contrôlé par un signal PWM provenant de la carte de contrôle du moteur.Deux caméras disposées en parallèle sont utilisées pour imager les puits disposés sur deux rangées, ce qui réduit le mouvement nécessaire. Le mouvement sur un axe est réalisé à l'aide d'un mécanisme de vis sans fin actionné par un moteur à courant continu, piloté par la carte de commande du moteur. Le prototypage a été effectué sur presque toutes les parties de la conception proposée. L'assemblage de la vis sans fin a été testé avec succès, et les tests sur un modèle thermique ont démontré avec succès que le contrôle thermique binaire atteint la plage de température nominale. Certains points concernant la conception restent à définir, et une vérification et une validation plus approfondies de la conception restent à effectuer.

In 21 century finned surfaces are used in almost all condensers to enhance their heat transfer capabilities. A lot of different models are presented in the literature: on horizontal and vertical finned tubes, inside finned tubes. The validation method of the theoretical models is based on comparison between measurement of average heat transfer coefficient and one calculated by the model. But in this case it is impossible to validate all approaches made in the theory.<p>\ / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

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