INTRODUCTION

Motivation
• Low through-thickness thermal conductivity of typical composite materials
• Measure and enhance the through-thickness thermal conductivity for composites

Objectives
• Record the temperature gradient due to sample surface heterogeneity
• Investigate the role of natural convective boundary condition influence on heat transfer efficiency

EXPERIMENTAL METHOD SETUP

• Vertical implementation: prevention of asymmetric natural convection

SURFACE EMMISSIVITY AND HEAT TRANSFER COEFFICIENT EVALUATION

• Evaluate the thermal grease surface emissivity to acquire the real temperature based on infrared image reading

3D FINITE ELEMENT MODELING

VALIDATION TEST AND COMPOSITES TEST

• Stainless steel sample test
Effective k calculation error <4%
• Composites test
• Surface Temperature gradient profile

RESULTS

• Effective thermal conductivity characterization k=-q^'' L/(T_botave-T_topave)
• Good temperature agreement on the convection surface at optimal h2*
• More significant enhancement for copper distributed 3TEX samples

SUMMARY

• An apparatus was modified to be integrated with infrared camera and FE modeling for a novel through-thickness thermal conductivity measurement technique with the capability to capture surface temperature unevenness.
• Multiple copper rods distributed through the thickness enhance thermal conductivity significantly.

ACKNOWLEDGEMENTS

This work is supported by National Science Foundation (CMMI-0970002).