Accession Number : ADA261050


Title :   Thermocapillary Flow Near a Cold Wall


Descriptive Note : Technical rept., Jan-Dec 1992


Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA


Personal Author(s) : Canright, David


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a261050.pdf


Report Date : 20 Jan 1993


Pagination or Media Count : 44


Abstract : The following model problem examines the thermocapillary feedback mechanism important at the edge of weld pools and other materials processes. A pool of liquid with a flat horizontal free surface is bounded on one side by a vertical solid wall, which is maintained at a cold temperature to unit depth, and at a warmer temperature below; far away the fluid is at the warmer temperature. Surface tension is a decreasing function of temperature, so that the surface thermal gradient drives flow toward the corner. When convection is vigorous, the flow compresses the thermal gradient which is driving the flow; this positive feedback results in small local length scales and high velocities near the corner. This problem is examined through a detailed scaling analysis and through numerical simulation for a range of parameters.... Thermocapillary flow.


Descriptors :   *CONVECTION(HEAT TRANSFER) , *CAPILLARITY , *WELDING , VELOCITY , SIMULATION , TEMPERATURE , MODELS , EDGES , HIGH VELOCITY , FLUID FLOW , LIQUID METALS , GRADIENTS , SURFACE TENSION , VISCOUS FLOW , SOLIDS , WELD METAL , WELDS , FEEDBACK , WALLS


Subject Categories : Fabrication Metallurgy
      Fluid Mechanics
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE