Numerical computation of thermally controlled steam bubble condensation using Moving Particle Semi-implicit (MPS) method

Numerical investigation of vapor bubble condensation characteristics of subcooled flow boiling in vertical rectangular channel

Numerical simulation of bubble condensation using CF-VOF

Numerical simulation of single bubble condensation in subcooled flow using OpenFOAM

The evaluation of the diffuse interface method for phase change simulations using OpenFOAM

Experiments have been carried out to investigate direct contact condensation of saturated vapor bubbles introduced into a quiescent subcooled water environment. The experiments were performed for a range of pressures from atmospheric to 1 MPa, for subcooling from 10 to 70 K, and for initial bubble diameters of about 10 mm. Flow visualization by highspeed motion pictures was based on a frame-by-frame analysis. The photographs show that the successive shapes of the bubbles during their collapse histories proceeded from a sphere to a hemisphere, to an ellipsoid, to a sphere, and finally to collapse. Two-dimensional photographs clearly show that the cavities of the bubbles during their collapse histories proceeded from the bottom to the top. The time to collapse increased with increasing pressure difference. The rising velocities of the bubbles were essentially constant, with an overall range of 20–25 cm/s.

Condensing phenomena of a single vapor bubble into subcooled water

Experiments were conducted for the condensation and disappearance of vapor bubbles jetted from atmosphere through a single nozzle into subcooled water under medium pressure. The findings are as follows: (1) The life of vapor bubbles -- from their generation to disappearance -- is proportional to the initial diameter. (2) Since the initial diameter of bubbles and the life can be quantitatively determined with a high accuracy, the average heat transfer until bubble disappearance can be estimated. (3) The experimental formula obtained by Brucker et al. through experiments conducted under higher pressure than in this study is applicable to the results of the experiments reported here. (7 figs, 4 refs)

Study on condensation of a single vapor bubble into subcooled water. 2nd report, experimental analysis

The structure and numerically predicted results of a new Stirling engine with a circular disk heat exchanger consisting of pin-fin arrays are presented. Pin-fin arrays are carved into the circular heat exchanger disk's face. An annular cover plate is attached to these tips. A cooler of similar shape is located. So-called “α”, “β” and “γ” configurations are capable in present engine. Numerical prediction of power employing second-order approximation method is carried out in so-called “β” configuration engine case. The fluid resistances of many parts are regarded and some mechanical friction losses are regarded. The predicted engine output becomes 1 kW with the temperature of 773 and 298 [K] on the heating side and cooling side, respectively. In conclusion, the Stirling engine described here is suitable for biomass and solar use because its heater shape is circular and has unique feature that it doesn't need any heat exchanger pipe.

https://www.jstage.jst.go.jp/article/kikaib1979/71/701/71_701_260/_pdf

Study of Stirling Engine Having Heat Exchangers Consisting of Pin-Fin Arrays

It has been recognized that the steam accumulator plays an important role as one of thermal energy storage system and was used at hospitals, hotels and food factories in recent years. Experiments have been carried out to investigate direct contact condensation of saturated steam into a quiescent subcooled water environment. They were performed for subcooling from 20 - 70°C, for atmospheric pressure, and for various type of orifice ( single-orifice, multi-orifice and porous-disc-orifice ). The phenomena were observed by means of high speed shadowgraphy using a rotating prism camera. The phenomena were also visualized by techniques of liquid crystal using a still camera. The effect of bulk temperature in a water tank and the difference among a single-orifice, a multi-orifice and porous-disc-orifice were discussed and good predictive results for the visualization of thermal flow in a quiescent subcooled water environment were obtained.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Observational Study On Thermal Flow And Condensation Of Injecting Steam From Various Submerged Orifices

By the injecting nozzles' position of the pressurized head tank attached to the water bathtub, water jet flow can be injected to the rectangular water bathtub or diffuser shape water bathtub. The fluid velocity can be set to two kinds of speeds in these bathtubs. The purpose of present study is to visualize flow pattern inside water bathtub. The water bathtub having uniform water flow can be utilized as a very small pool in which everybody can enjoy swimming or can practice physical exercise for health. The utility values for water bathtub can be found in many fields. In this study, we use small transparent rectangular water bathtub made of acrylic resin and materials for the observation of flow pattern inside in it. The method how to make uniform flow inside water bathtub is by injecting water from many jet nozzles attached to the pressurized water tank situated in the front side of water bathtub. Then the downstream water is rejected from overflow bank attached to the rear side of water bathtub. The experiment to visualize flow inside bathtubs is carried out by using liquid and powder as tracers. Much technical knowledge is obtained by the present study.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Shuya Kamei

Papers

Condensing phenomena of a single vapor bubble into subcooled water

Study on condensation of a single vapor bubble into subcooled water. 2nd report, experimental analysis

Study of Stirling Engine Having Heat Exchangers Consisting of Pin-Fin Arrays

Observational Study On Thermal Flow And Condensation Of Injecting Steam From Various Submerged Orifices

Visualization study of the stream line and secondary flow in the running water bathtub