Category: TWO-PHASE FLOW

In this webinar, we will discuss flow distribution and pressure drop for single T-junctions and manifolds by describing the T-junction resistance coefficients and how they vary with flow conditions and geometry describing manifold geometry and outlining the differential and discrete equation approaches for solving the flow distribution problem demonstrating which approach...
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Based on recent research, HTRI has developed a new pressure drop method for inclined cocurrent condensation. In this webinar, we discuss the effect of tube inclination on two-phase flow regimes and pressure drop. The performance of the existing inclined condensation pressure drop method is assessed against data, and an improved pressure...
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In this webinar, we describe pressure drop correlations and provide recommendations for their use. Many flow circuits include pipe diameter variations and piping components such as orifice plates, contractions, and expansions. Accurate prediction of the single- and two-phase pressure drops across these components is necessary to calculate the total pressure drop...
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Adiabatic air-water studies were performed in a large pipe with vertical downflow, using a section of the HTRI air-water flow loop. High-speed videos of the downflow were analyzed to estimate the void fraction and to obtain a flow regime map. A falling film annular flow regime was observed for most flow...
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Over the past several decades, the accuracy and usability of computational methods have substantially improved. This report reviews the complicated physics of two-phase flow and phase change, presents the equations of motion for a two-phase flow with various closure models, and compares current computational approaches. Although inadequate for the entire spectrum of...
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HTRI recently concluded research in the following topics: Vertical Upflow – pressure drop and void fraction Vertical Upflow – flow regime map Vertical Downflow – pressure drop and void fraction Vertical Downflow – flow regime The details of the research, results, and discussions have been published in HTRI research reports TPF-14,...
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Boiling, condensation, and multi-phase flows exist in many heat exchanger applications. This webinar describes the basic ideas used in heat transfer and pressure drop calculations of two-phase flow. It discusses theoretical and empirical models, a flow regime-based approach, and an overview of experimental research in the field....
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To gain further insight into kettle reboiler operation and improve Xist® models, we simulated several kettle reboilers in two dimensions using CFD. The two-phase simulation results show good agreement with pressure drop and vapor volume fraction measurements from the literature. However, recirculation ratios calculated from the CFD results are substantially greater...
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After briefly surveying the challenges of modeling condensation with computational fluid dynamics (CFD), we apply two relevant two-phase models in ANSYS® FLUENT® with varying degrees of success. Homogeneous nucleation in a Laval nozzle is well predicted, while the more interesting and relevant intube film condensation is plagued by grid resolution, model...
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