Interfacial Shear in Two-Phase Wavy Flow in Closed Horizontal Channels

1974 ◽  
Vol 96 (2) ◽  
pp. 97-102 ◽  
Author(s):  
E. Kordyban
Keyword(s):  
Shear Stress ◽  
Pressure Drop ◽  
Wall Shear Stress ◽  
Cross Section ◽  
Water Surface ◽  
Interfacial Shear Stress ◽  
Interfacial Shear ◽  
Channel Cross Section ◽  
Two Phase ◽  
The Waves

The interfacial shear stress for air flowing over a wavy water surface was determined experimentally in a closed horizontal channel by measuring the pressure drop and the structure of the water surface. The wall shear stress was measured with the aid of a Preston gauge. The range of tests included the conditions where the waves were large in comparison to the channel cross section. The equivalent sand roughness determined from the resistance formula for rough walls in fully turbulent flow was found to be related to the rms wave height through ks = 32Δh.

Steady Flow in Tubes of Slowly Varying Cross Section

1978 ◽  
Vol 45 (3) ◽  
pp. 475-480 ◽  
Author(s):  
D. A. MacDonald
Keyword(s):  
Shear Stress ◽  
Pressure Drop ◽  
Wall Shear Stress ◽  
Cross Section ◽  
Tube Wall ◽  
Fluid Motion ◽  
Pressure Rise ◽  
Wall Profile ◽  
Actual Shape ◽  
Viscous Fluid Motion

This paper studies steady incompressible viscous fluid motion in axisymmetric tubes of slowly varying cross section. Theory, which is independent of the actual shape of tube wall profile, is developed and a number of illustrative examples are studied. Results which portray the behavior of pressure drop (pressure rise, in some cases) and wall shear stress are presented.

scholarly journals Uncertainty quantification of RELAP5/MOD3.3 for interfacial shear stress during small break LOCA

2021 ◽  
Vol 7 (3) ◽  
pp. 1-7
Author(s):  
Hanh Tung DUONG ◽  
Hoang Anh NGUYEN ◽  
Richard TREWIN ◽  
Hiroshige KIKURA
Keyword(s):  
Shear Stress ◽  
Nuclear Power ◽  
System Analysis ◽  
Fluid Model ◽  
Interfacial Shear Stress ◽  
Reactor Core ◽  
Computer Code ◽  
Interfacial Shear ◽  
Two Phase ◽  
Two Fluid

The Best-Estimate Plus Uncertainty (BEPU) is applied as Deterministic Approach forsafety analysis of Nuclear Power Plant using the system analysis code. The system analysis code such as Relap5/Mod3.3 is required to be able to simulate the thermal-hydraulic behavior of nuclear reactor in some accident scenarios. Relap5/Mod3.3 is developed based on two-fluid models and 6 conservation equations for each phase which challenge for mathematical modeling such as onedemensional equation, time-dependent equation, multidimensional effects or complicated geometry. Thus, it is necessary to verify the applicability of a system analysis code that is able to predict accurately the two-phase flow such as interfacial shear stress between two phases: liquid and gases. It is also important to know the prediction uncertainty by using computer code due to the constitutive relation in the two-fluid model equation. In PWR’s Small-Break LOCA (SB-LOCA) accident, the loop-seal clearing is important phenomena where we would like to know how much water (reflux condensation) will be come into the reactor core from Steam Generator. In this work, the UPTFTRAM simulated the counter-current flow in Loop-seal Clearing between vapor and liquid in Loopseal during SB-LOCA is used to verify the applicability of Relap5/Mod3.3 and the experimental data are used to compare with simulation results. Moreover, the uncertainty evaluation or estimation is also investigated by applying the statistical method or BEPU in which the SUSA program developed by GRS is used.

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