Bio: Swapan Paruya is an academic researcher from National Institute of Technology, Durgapur. The author has contributed to research in topics: Boiling & Subcooling. The author has an hindex of 7, co-authored 22 publications receiving 119 citations.
TL;DR: In this paper, the authors analyze DWO in several boiling channels with varying lengths (Froude number) adopting moving node scheme and fixed node scheme (FNS) to evaluate the capability of the methods.
TL;DR: In this article, the authors present a review of the state-of-the-art of theoretical investigations on the flow oscillations that occur in a boiling natural circulation loop and develop a high-fidelity model that is capable of predicting nature of flow instabilities more accurately.
TL;DR: In this article, the authors investigated numerically the dynamics of bubble growth and departure in pool boiling at surface in low pressures using the asymptotic solution derived from a semi analytical method and considering both macrolayer and microlayer evaporation.
TL;DR: In this article, the authors report uncontrolled behavior and controlled behavior of boiling flow in a mini-channel excited by step perturbation and periodic perturbations and demonstrate the performance of nonlinear model predictive control (NMPC) in reducing the chaotic oscillations.
TL;DR: In this paper, the authors presented power spectrums, attractor reconstructions, and Hurst exponents for the analysis of the experimental data and showed that the primary oscillations are very similar to geysering instability.
Abstract: Flow instabilities in a natural circulation boiling loop at a low pressure are reported. The oscillations at boiling incipience are primarily chaotic and bifurcate to quasiperiodic ones depending on inlet subcooling ΔTsub and heater power Q. They also strongly depend on water volume Φ in the loop. We have presented power spectrums, attractor reconstructions, and Hurst exponents for the analysis of the experimental data. The analysis shows that the primary oscillations are very similar to geysering instability. Chaotic oscillations occur at low ΔTsub or high Q, whereas quasiperiodic oscillations occur at high ΔTsub or low Q. Our experiments also suggest that wall superheat exceeding a critical value triggers the instability. © 2013 American Institute of Chemical Engineers AIChE J, 60: 375–386, 2014
01 Aug 1953
TL;DR: In this paper, a solution for the radius of the vapor bubble as a function of time is obtained which is valid for sufficiently large radius, since the radius at which it becomes valid is near the lower limit of experimental observation.
Abstract: The growth of a vapor bubble in a superheated liquid is controlled by three factors: the inertia of the liquid, the surface tension, and the vapor pressure. As the bubble grows, evaporation takes place at the bubble boundary, and the temperature and vapor pressure in the bubble are thereby decreased. The heat inflow requirement of evaporation, however, depends on the rate of bubble growth, so that the dynamic problem is linked with a heat diffusion problem. Since the heat diffusion problem has been solved, a quantitative formulation of the dynamic problem can be given. A solution for the radius of the vapor bubble as a function of time is obtained which is valid for sufficiently large radius. This asymptotic solution covers the range of physical interest since the radius at which it becomes valid is near the lower limit of experimental observation. It shows the strong effect of heat diffusion on the rate of bubble growth. Comparison of the predicted radius‐time behavior is made with experimental observations in superheated water, and very good agreement is found.
TL;DR: An updated review of two-phase flow instabilities including experimental and analytical results regarding density-wave and pressure-drop oscillations, as well as Ledinegg excursions, is presented in this article.
TL;DR: In this article, the thermal-hydraulics of a Boiling Water Nuclear Reactor were investigated and shown to have thermal properties similar to those of a conventional nuclear Reactor.
Abstract: (1978). The Thermal-Hydraulics of a Boiling Water Nuclear Reactor. Nuclear Technology: Vol. 39, No. 3, pp. 330-330.
TL;DR: A review of published work on the physics and modelling of flashing flows is presented in this paper, where the authors provide a brief but comprehensive overview of available theoretical models for these sub-phenomena as well as general modelling frameworks.