We propose a system for measuring entropy 1 variations, S, in thermal systems using pyroelectric sensors. 2 These sensors convert time-dependent temperature variations 3 into electrical current. Consequently, heat and temperature 4 variations are obtained, and sensor entropy is inferred. Various 5 polyvinylidene fluoride and lead zirconate titanate sensors have 6 been tested. Two types of measu...

In nature, dissipative fluxes of fluid, heat and/or reacting species couple to each other and may also couple to deformation of a surrounding porous matrix. We use the well-known analogy of Hele-Shaw flow to Darcy flow to make a model porous medium with porosity proportional to local cell height. Time- and space-varying fluid injection from multiple source/sink wells lets us create many differe...

Coastal California has evolved through a series of plate tectonic interactions that significantly affected the geologic, thermal, and hydrocarbon maturation histories of the area. Numerical solutions for steady-state heat transfer are used to estimate temperature suppression resulting from plate subduction along coastal California, and to model thermal refraction within the Pismo basin. Numeric...

Abstract The rapid economic growth of Southeast Asian countries is followed by accelerated population and energy demand growth. On the other hand, region still relies heavily on fossil fuels as primary source electricity. As a result, there growing concern about future regional sustainability. Space cooling has become one fastest-growing sectors. Introducing new space technology capable providi...

It was recently shown theoretically that the time-dependent heat conduction equation is form invariant under curvilinear coordinate transformations. Thus, in analogy to transformation optics, fictitious transformed space can be mapped onto (meta)materials with spatially inhomogeneous and anisotropic heat-conductivity tensors in the laboratory space. On this basis, we design, fabricate, and char...

The time-dependent Maxwell nanofluid flow with thermophoretic particle deposition is examined in this study by considering the solid–liquid interfacial layer and nanoparticle diameter. governing partial differential equations are reduced to ordinary using suitable similarity transformations. Later, these solved Runge–Kutta–Fehlberg’s fourth fifth-order method via a shooting approach. An artific...

This paper focuses on considering two inverse source problems (ISPs) for a multi-term time-fractional evolution equation with an involution term, interpolating the heat and wave equations. The fractional derivatives are defined in Caputo's sense. ISPs proved to be ill-posed sense of Hadamard. Recovering space dependent term from over-specified data given at some time constitute first ISP, while...

Temperature boosting of waste heat from spacecraft by means of heat pumps makes it possible, under some conditions, to achieve considerable savings in radiator area and mass. This study considers several possibilities for employing workactuated and heat-actuated heat pumps (WAHP and HAHP, respectively) for this purpose. In the former case, the spacecraft power source is required to generate ext...