Solidification characteristics in a spherical capsule integrated with pin fins and rectangular fins - a comparative study

This study aims at investigating the solidification characteristics in a spherical capsule with pin fins and rectangular fins of same length and volume immersed in a constant temperature bath (-6°C, -9°C, -12°C). The fins are made of copper and are attached to the inner surface of the spherical capsule. The fin lengths correspond to the annulus fill volume margin of 75% taken on the inside wall of the spherical container. The findings showed that the overall solidification period of the capsules with rectangular fins was reduced. Also, the subcooling phenomena is completely eliminated at bath temperature of -6°C. Results also indicated that 50% PCM mass is reduced effectively with the provision of fins. Thus, with the employment of rectangular fins better potential energy savings can be attained when operated at partial charging mode at higher bath temperature.

The math modeling research of constant temperature bath

This paper studies how the temperature in the bathroom keeps changing when people bathe in the bathtub. The shape, capacity, behavior and body posture of people in the bathroom are considered. In fluid mechanics point of view, we consider the impact of the flow of heat transfer, by the energy differential equations and boundary-layer momentum to establish a set of PDE, and use Laplace operator rewrite it. We use finite difference method, with Taylor series expansion. We use the function value of grid nodes of difference quotient instead of control equation of derivative, and discretize it, and solve the heat conduction equation.

Transient Diffusion in Triangular Cylinders

A heated triangular cylinder is suddenly cooled in a constant temperature bath. The transient heat conduction problem is transformed to the Helmholtz equation related to the vibration of membranes. Using the membrane analogy, exact analytic solutions for the transient heat conduction problem for three triangular cross sections are found.

A HISTORICAL ATLAS OF OBJECTIVITY

The mythical scientist in early twentieth-century America cut a lone figure, “impersonal as the chill northeast wind” and “oblivious of everything save his experiment.” He toiled through the night in his laboratory, “a place unimpressive and unmagical save for the constant-temperature bath with its tricky thermometer and electric bulbs,” as if working in the lab were a prayer that promised illumination—“alone, absorbed, [and] contemptuous of academic success and of popular classes,” he knew all about material forces, but he was blind to the vital force that created all others. Accustomed to the “beautiful dullness of long labors,” he remained “illimitably ignorant” of literature, art, and music. He believed that unerring techniques in experimentation, impartial observations, and exquisitely minute calculations would bring progress—a steady march toward the truth. He chose the highest calling in the world because he was “intensely religious—so religious that he will not accept quarter-truths, because they are an insult to his faith.” He was “so devoted to Pure Science . . . that he would rather have people die by the right therapy than be cured by the wrong. Having built a shrine for humanity, he wanted to kick out of it all mere human beings.” This autocratic figure, brilliantly insane and tyrannically honest, embodied the cult of science and objectivity.

Heat Transfer Augmentation Using Fins of Various Cross Section Under Steady State

Extended surfaces or fins are used to enhance the heat transfer rate between a solid and adjoining fluid. An experimental investigation is carried out in the present work to establish the heat transfer characteristic for fins made of varying material and varying cross section. Three different fin sections, circular, square and triangular are considered for the study. Aluminum, brass and copper fins with varying cross section along the length are tested under steady state. Experimental set up consists of a constant temperature bath to maintain desired thermal boundary condition at one end of the fin. Copper constantan thermocouples are used to measure the temperature at different sections of the fin. The experimental results of temperature distribution of the fins are compared with the analytical and numerical results. The effectiveness of fins along the length for all section and materials is also compared.

Controlled-Humidity XRD Analyses: Application to the Study of Smectite Expansion/Contraction

Smectites are clay minerals that expand and contract dramatically in response to changes in water vapor pressure. The expansion/contraction behavior of smectite has considerable importance in engineering applications (such as the stability of building foundations and the integrity of clay barriers) and affects hydrologic properties. To understand this behavior we have analyzed several purified, homoionic smectite standards over a wide range of relative humidities using X-ray powder diffraction (XRD) and a new computer-automated humidity-control system.Humidity was controlled by mixing dry N2 with H2O-saturated (“wet”) N2 produced with a gas-washing bubbler held in a constant-temperature bath set at 35°C. Mixing of wet and dry N2 was controlled with automated MKS mass-flow controllers.