ICONE23-1845 CFD STUDY ON INLET FLOW BLOCKAGE ACCIDENTS IN MULTI-LAYER ANNULAR FLOW CHANNELS

A new method of estimating gas and liquid flow rates is proposed for a gas-liquid two-phase flow system. The method involves measurement of pressure drops in horizontal and vertical flow channels, and calculation of flow rates by Lockhart-Martinelli correlation. The method does not require the insertion of sensing device into the flow channel and does not rely on previously calibrated correlations. Experiments are performed in slug, froth and annular flow regimes for an air-water system, and the usefulness of the proposed method is examined. The results reveal that gas and liquid flow rates can be estimated with the accuracies of 45% for gas phase and 37% for liquid phase with respect to mean values.

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The Influence of Tabs on Different Area Ratio Short Annular Diffusers

Volume 2C: Turbomachinery ◽

10.1115/gt2014-25569 ◽

2014 ◽

Author(s):

D. J. Cerantola ◽

A. M. Birk

Keyword(s):

Boundary Layer ◽

Reynolds Number ◽

Layer Thickness ◽

Boundary Layer Thickness ◽

Pressure Coefficient ◽

Area Ratio ◽

Back Pressure ◽

Swirl Number ◽

Inlet Flow ◽

Flow Blockage

Square tabs were placed on the base of an ellipsoidal centre body in annular diffusers with length to inlet height of 12. Tests were completed with an inlet Reynolds number of 1 × 105, swirl number of 0.71, and inlet flow blockage of 0.02–0.04. Four outer walls were manufactured with area ratios of 1.61, 1.91, 2.73, and 6.18. The tabs with a projected height equivalent to the boundary layer thickness were effective at reducing the outlet distortion but at a pressure penalty for the three smaller diffusers. The largest diffuser improved back pressure coefficient 4.6% with four tabs providing a blockage of 4.7% over its bare diffuser but was 42% lower than that obtained by the AR = 2.73 diffuser with no tabs.

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Phase Distribution of Slug-Annular Flow at a Horizontal Miniature T-Junction

2010 14th International Heat Transfer Conference, Volume 3 ◽

10.1115/ihtc14-23174 ◽

2010 ◽

Cited By ~ 1

Author(s):

Shuangfeng Wang ◽

Kui He ◽

Jianzhen Huang

Keyword(s):

Flow Pattern ◽

Annular Flow ◽

Two Phase Flow ◽

Phase Distribution ◽

Side Branch ◽

Superficial Velocity ◽

Phase Flow ◽

Two Phase ◽

Inlet Flow ◽

The Impact

In this paper, the behavior of nitrogen-water two-phase flow at a horizontal miniature T-junction with main and side branch of 500 μm diameter was studied. When the inlet flow pattern is slug-annular, the impact of upstream gas and liquid superficial velocity on phase distribution of two-phase flow in the miniature T-junction were investigated in detail. It is found that increasing liquid superficial velocity slightly increase the maldistribution at this work scope. Gas superficial velocity has complex impact on the maldistribution due to different proportion of sub-patterns, and pressure has no impact on phase distribution.

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