The present work aims at studying the effects of orientation, size, position, and the combination of multiple internal diathermal obstructions in a fluid-saturated square porous enclosure, generally encountered in thermal insulations. The overall objective is to suppress the natural convection fluid flow and heat transfer across a differentially heated porous enclosure. To serve this purpose, multiple diathermal obstructions are employed to mechanically protrude into a porous medium. It is sought to estimate the effect of various types of orientation, clustering and alternate positioning of obstructions by considering number of obstructions (Np), length of obstructions (λ), modified Rayleigh number (Ra*) on local and average Nusselt number (Nu). The Darcy model for porous media is solved using Finite difference method along with Successive Accelerated Replacement scheme. One of the findings is that the value of the Nusselt number decreases by increasing both, the number of obstructions as well as the length of obstructions irrespective of its orientation and positioning. The reduction in Nusselt number is significant with obstructions attached on lower half of the hot wall and/or on upper half of cold wall. In addition, the overall reduction in Nusselt number is slightly greater with obstructions attached explicitly to the cold wall.
In this article, the imperial idea and civilising missions in the Habsburg Monarchy, mainly of the nineteenth century, are refracted through the prism of the legacy of enlightened absolutism. The article tries to dispel mythologies about its demise around 1800, and about those who could subscribe to its programme throughout the nineteenth century. It questions templates of national history writing which too unanimously connect the Enlightenment to the origins of the various national revivals of the early nineteenth century, and discusses concrete examples of enlightened absolutism’s civilising impulses, among them law, Roman imperial patriotism, and the Catholic religion.