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Numerical simulation of short‐dwell coaters: Steady state flow patterns and pressure distributions
Author(s) -
Cao Zhenlei,
Esmail M. Nabil
Publication year - 1992
Publication title -
the canadian journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.404
H-Index - 67
eISSN - 1939-019X
pISSN - 0008-4034
DOI - 10.1002/cjce.5450700406
Subject(s) - coating , materials science , mechanics , dwell time , reynolds number , substrate (aquarium) , flow (mathematics) , penetration (warfare) , pressure gradient , volumetric flow rate , composite material , mathematics , physics , geology , turbulence , oceanography , medicine , clinical psychology , operations research
The steady state flow in a short‐dwell coater has been simulated by solving the two‐dimensional Navier‐Stokes equations in the primary pressure and velocity variables for substrate Reynolds numbers up to 1000. The small opening under the blade has very little effect on the flow patterns in the coating pond. However, it does have a significant effect on the pressure field in the pond. The pressure on the substrate surface, which controls liquid penetration during application, has a maximum value under the blade, near its tip. Low coating weights and high coating speeds lead to higher maximum pressure on the substrate. The operating pressure which must be applied to the blade can be predicted for a given coating weight and substrate velocity. For high substrate speeds and low coating weights, higher operating pressures are needed to keep the blade in position.