TTim is a free code for the semi-analytic simulation of transient flow in multi-layer systems consisting of an arbitrary number of layers. No grid or time-stepping is required, nor does a closed model boundary need to be specified in any of the layers. Currently, TTim includes multi-layer wells and line-sinks, which may be used to simulate transient flow to a variety of hydrogeologic features, including wells with a skin and wellbore storage, incompletely sealed abandoned wells, streams with leaky beds, vertical faults, and horizontal wells; transient forcing needs to be represented by a step function. Other features that may be simulated include vertical anisotropy and the delayed response of the water table. Behind the scenes of TTim, the Laplace-transform analytic element method is applied. TTim is written in Python, with Python scripts used as input files. TTim has many practical applications, including the design of riverbank filtration systems, analysis of aquifer tests near surface-water bodies, design and evaluation of recirculation wells, and modeling of the transient pressure response of proposed carbon geologic sequestration projects. In addition, the short and simple input files and the one-to-one link between analytic elements and hydrogeologic features make TTim well suited for education.RésuméTTim est un code libre de droit pour la simultation semi-analytique d’écoulement transitoire de systèmes multi-couches composés d’un nombre arbitraire de couches. Aucune grille ou pas de temps n’est requise, pas plus que la limite fermée du modèle doit être spécifiée pour l’ensemble des couches. Actuellement, TTim comprend des puits multi-couche et des points d’engouffrement, qui peuvent être utilisés pour simuler l’écoulement transitoire pour une variété de configurations hydrogéologiques, telles que des puits avec un effet de peau et un effet capacitif au puits, des puits abandonnés à étanchéité incomplète, des cours d’eau à lit infiltrant, des failles verticales, et des puits horizontaux; le forçage transitoire nécessite d’être représenté par une fonction en échelon. D’autres configurations pouvant être simulées comprennent l’anisotropie verticale et la réponse retardée du niveau piézométrique. Derrière le montage de TTim, la méthode analytique élémentaire de la transformée de Laplace est appliquée. TTim est écrit en langage Python, avec des scripts utilisés comme fichiers d’entrée. TTim possède plusieurs applications pratiques, telles que la conception de systyèmes d’infiltration au niveau des rives de cours d’eau, l’analyse des essais d’aquifère à proximité de cours d’eau, la conception et l’évaluation de puits permettant la recirculation de l’eau et la modélisation des réponses en régime transitoire de la pression dans le cadre de projets de séquestration géologique du CO2. De plus, les fichiers d’entrée sont courts et simples et la relation entre les éléments analytiques et les configurations hydrogéologiques rendent TTim approprié pour l’enseignement.ResumenTTim es un programa libre para la simulación semianalítica de flujo transitorio en sistemas multicapas consistentes en un número arbitrario de capas. No se requiere una grilla ni un paso temporal, tampoco es necesario especificar un modelo de bordes cerrados para ninguna de las capas. Actualmente, TTim incluye pozos multicapas y sumideros en líneas, que puede ser usado para simular el flujo transitorio para una variedad de aspectos hidrogeológicos, incluyendo pozos con un almacenamiento pelicular y en el pozo, pozos abandonados incompletamente sellados, corrientes con capas filtrantes, fallas verticales y pozos horizontales; las necesidades transitorias obligan a estar representadas por una función escalón. Otras características que pueden ser simuladas incluyendo la anisotropía vertical y la respuesta retardada de los niveles freáticos. Detrás de las presentaciones de TTim, se aplicó un método de elementos analíticos de la transformada de Laplace. TTim está escrito en Python, con escritura de Python usada como archivos de entrada. TTim tiene muchas aplicaciones prácticas, inclusive el diseño de sistema de filtración de las márgenes del río, análisis de ensayos de acuíferos próximos a los cuerpos de agua superficial, diseño y evaluación de pozos de recirculación, y modelado de respuesta transitoria de la presión en proyectos de secuestro geológico de carbón. Además, los cortos y simples archivos de entradas y el enlace uno a uno entre los elementos analíticos y los aspectos hidrogeológicos hacen que el TTim sea muy apropiado para la educación.ResumoO TTim é um software livre para simulação semi-analítica do escoamento transitório em sistemas multi-camada constituídos por um número arbitrário de camadas. O software não requer nenhuma discretização espacial ou passos de tempo, nem é necessário especificar um limite de modelo fechado para qualquer das camadas. Presentemente, o TTim inclui poços e sumidouros lineares multi-camada que podem ser usados para simular o escoamento transitório para uma variedade de entidades hidrogeológicas, incluindo poços com efeito de pele e com armazenamento, poços abandonados com selagem incompleta, cursos de água com leito drenante, falhas verticais e poços horizontais; o caráter transitório tem que ser representado por uma função em degraus. Outras funcionalidades que podem ser simuladas incluem a anisotropia vertical e a resposta diferida do nível freático. Por trás do TTrim é aplicado o método de elementos analíticos da transformada de Laplace. O TTim é escrito em linguagem Python, sendo usados ficheiros Python como entrada de dados. O TTim tem muitas aplicações práticas, incluindo o projeto de sistemas de filtração em margem de cursos de água, a análise de ensaios em aquíferos próximos de corpos de água superficial, o projeto e a avaliação de poços de recirculação e a modelação da pressão transitória resultante dos propostos projetos de sequestro geológico de carbono. Para além disso, os ficheiros de entrada, curtos e simples, e a conexão direta entre os elementos analíticos e as caraterísticas hidrogeológicas tornam o TTim bem adaptado ao ensino.
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