Soyuz/ACRV accommodation study

Included is a set of viewgraphs that present the results of a study conducted at the LaRC Space Station Freedom Office at the request of the Space Station Freedom Level 1 Program Office and the JSC ACRV Project Office to determine the implications of accommodating two Soyuz TM spacecraft as Assured Crew Return Vehicles (ACRV) on the Space Station Freedom (SSF) at the Permanently Crewed Capability (PCC) stage. The study examined operational as well as system issues associated with the accommodation of the Soyuz for several potential configuration options. Operational issues considered include physical hardware clearances, worst case Soyuz departure paths, and impacts to baseline operations such as Pressurized Logistics Module (PLM) exchange, Space Station Remote Manipulator System (SSRMS) attachment, Extravehicular Activity (EVA), and automatic rendezvous and docking (AR&D). Systems impact analysis included determining differences between Soyuz interface requirements and SSF capabilities for the Electrical Power System (EPS), Thermal Control System (TCS), Communications and Tracking (C&T), Audio-Video Subsystem (A/V), Data Management System (DMS), and Environmental Control and Life Support System (ECLSS). Significant findings of this study have indicated that the current AV capability of the Soyuz will need to be increased to provide adequate departure clearances for a worst case escape from an uncontrolled SSF and that an interface element will be required to mate the Soyuz vehicles to station, provide for AR&D structural loads, and to house Soyuz-to-SSF system interfaces

Development of a wide-spectrum thermochemical code with application to planar reacting and non-reacting shocks

Mención Internacional en el título de doctorThe recent scientific and technological advancements have underscored the critical necessity for reliable, robust, and efficient numerical codes capable of predicting the chemical composition and properties of complex mixtures at chemical equilibrium. In response to this demand, this thesis presents the development and validation of a novel open-source thermochemical code called Combustion Toolbox (CT). This tool is designed to determine the equilibrium state of multi-species mixtures in gaseous or pure condensed phases, including ions. The code incorporates a comprehensive suite of algorithms, ranging from fundamental chemical equilibrium problems to complex computations of steady shock and detonation waves in various flow configurations, as well as predictions of rocket engine performance. Implemented in MATLAB, CT is accompanied by a user-friendly graphical user interface, ensuring flexibility and accessibility for all users. Extensive validation demonstrates excellent agreement with established codes such as NASA’s CEA, Cantera within Caltech’s Shock and Detonation Toolbox, and the recent Thermochemical Equilibrium Abundances code. CT has been utilized in all of the studies presented in this thesis, demonstrating its reliability and versatility. The second part of the thesis delves into the theoretical analysis of reactive and nonreactive shocks propagating through non-homogeneous conditions. Conducting experiments and high-fidelity simulations in this field can be challenging and computationally expensive. In this context, linear interaction analysis has emerged as a valuable tool to evaluate the hydrodynamical aspects contributing to the amplification of disturbances across the shock. Two prominent cases are investigated. Firstly, the study focuses on detonations with inhomogeneities in the upstream fuel mass fraction. The findings reveal that, in most cases, the detonation propagation speed is higher than in equivalent homogeneous scenarios. Subsequently, the investigation shifts towards the interaction of hypersonic shocks with turbulent flows, incorporating the associated thermochemical effects in single-species diatomic gases. The analysis is further extended to multi-species mixtures using CT, with a particular emphasis on air. These studies demonstrate that thermochemical effects arising at hypersonic velocities significantly enhance turbulent fluctuations in the post-shock gas compared to the simplified thermochemical frozen gas assumption.Los avances científicos y tecnológicos recientes han destacado la necesidad crítica de contar con códigos numéricos fiables, robustos y eficientes capaces de predecir la composición química y las propiedades de mezclas complejas en equilibrio químico. En respuesta a esta demanda, esta tesis presenta el desarrollo y la validación de un novedoso código termoquímico de código abierto llamado Combustion Toolbox (CT). Esta herramienta permite determinar el estado de equilibrio de mezclas multiespecie en fases gaseosas o condensadas puras, incluyendo iones. El código incorpora una amplia gama de algoritmos, desde problemas fundamentales de equilibrio químico hasta complejos cálculos de ondas de choque y detonación estacionarias en varias configuraciones de flujo, así como predicciones del rendimiento de motores cohete. Implementado en MATLAB, CT cuenta con una interfaz gráfica de usuario fácil de usar, que garantiza flexibilidad y accesibilidad para todos los usuarios. Se ha realizado una extensa validación que demuestra una excelente concordancia con códigos establecidos como el CEA de la NASA, Cantera y Shock and Detonation Toolbox del Caltech, así como el reciente código Thermochemical Equilibrium Abundances. CT se ha utilizado en todos los estudios presentados en esta tesis, demonstrando su fiabilidad y versatilidad. En la segunda parte de la tesis, se analizan los choques reactivos y no reactivos que se propagan en condiciones no homogéneas. Realizar experimentos y simulaciones de alta fidelidad en este campo puede ser desafiante y costoso computacionalmente. En este contexto, el análisis de interacción lineal ha surgido como una herramienta valiosa para evaluar los aspectos hidrodinámicos que contribuyen a la amplificación de las perturbaciones a través del choque. Se investigan dos casos destacados. En primer lugar, el estudio se centra en las detonaciones con inhomogeneidades aguas arriba de la fracción másica del combustible. Los resultados indican que, en la mayoría de los casos, la velocidad de propagación de la detonación es mayor que en escenarios homogéneos equivalentes. Posteriormente, la investigación se centra en la interacción de choques hipersónicos con flujos turbulentos, incorporando los efectos termoquímicos asociados en gases diatómicos de una sola especie. El análisis se extiende además a mezclas multiespecie utilizando CT, con un énfasis particular en el aire. Estos estudios demuestran que los efectos termoquímicos que surgen a velocidades hipersónicas aumentan significativamente las fluctuaciones turbulentas en el gas posterior al choque en comparación con la aproximación de gas termoquímicamente congelado.Programa de Doctorado en Mecánica de Fluidos por la Universidad Carlos III de Madrid; la Universidad de Jaén; la Universidad de Zaragoza; la Universidad Nacional de Educación a Distancia; la Universidad Politécnica de Madrid y la Universidad Rovira iPresidente: Francisco José Higuera Antón.- Secretario: Carlos Manuel del Pino Peñas.- Vocal: Bruno Dene