Three-dimensional film thickness distribution of horizontal tube falling film with droplet and sheet flow

Discontinuous and Transient Behavior Evolutionary Laws of Flow and Temperature Characteristics of Droplet Mode over a Horizontal Tube Falling Film

“…The simulation results of film thickness were also compared with the experimental result to verify the CFD calculation model, and the present results were plotted against spreading time and circumferential angle = 90° for one droplet period in Figure and found that the simulated results and the experimentally measured fluctuated had similar amplitude ranges and time periods. Here, it was important to note that the emergency moment of the liquid film fluctuation pattern was slightly later than the results in the literature about 20 ms, and the film thickness was about 10% thicker than the results of Chen et al due to the small tube spacing and diameter, which favored the increase of the liquid film thickness. By comprehensively considering the evolution law of film thickness and droplet morphology, the constructed three-dimensional simulation model could reproduce the physical process and produce accurate and credible results.…”

“…The effect of the flow pattern on the circumferential and axial film thickness distribution under countercurrent gas flow conditions was discussed by Li et al The film thickness appeared to be unstable and irregular with the maximum film thickness being approximately twice as large as the minimum. Chen et al indicated that the three-dimensional film thickness showed a fairly uniform distribution between 100 and 200 μm before impact and increased sharply to about 400 μm at t = 35 ms. Therefore, the thickness decreased in two directions and leveled off until a new droplet impact occurred.…”

Falling Film Flow and Heat Transfer of Cryogenic Liquid Oxygen on Different Structural Surfaces

“…In the present study, because the plate length is only 60 mm and the simulation Re is below 1600, thus, we chose the laminar model to simulate the film flow on the inclined plates. For the film on the horizontal tube, we acquired the film flow pattern of the present studied fluids in sheet flow at Re ≥ 634, based on Equation (6), which is defined as the critical Re for the jet-sheet flow transition [33]. Moreover, it was measured that the laminar film conditions exist up to a film Reynolds number of about 2000 [34].…”

“…John et al [5] compared the performance of eight liquid distributors for the film flow over horizontal tube banks. By using the chromatic confocal displacement sensor, Chen et al [6] measured the film thickness on the horizontal tube under the droplet and sheet flow. Chen et al [7] proposed a correlation to predict the flow pattern transitions over enhanced tubes with 2D integral fins based on the experimental data.…”

“…The working fluids studied in the existing literature are mainly concentrated in pure water [5][6][7][8]10,11,13,19,23,25], seawater [3], oil sewage [15,16], LiBr solution [17], freon refrigerant [9,20,22], ethylene glycol aqueous solution [14], potassium formate aqueous solution [24], ionic fluid [21,22]. For the cryogenic liquid, Pavlenko et al [26] measured the film flow of cryogenic liquid nitrogen on the surfaces with complex geometry, and found the microstructure has a significant influence on the film spreading progress.…”