A study on the effect of heat transfer methods

on orthotic preparation time

Vladimir Solovjov – MeEn 340Winter 2008

Eric RadfordKeith StolworthyJonathan Woahn

THEPROJECT

•Total process in less than 30 minutes•Heating the orthotic blank is an important process•Oven has various heating settings

•Temperature•Heat method (Bake vs. Convection)

Objective: Model the effect that varied heat methods have on preparing the orthotic

THEMODEL

Orthotic Blank

Radiative Heat Convective Heat

Conductive Heat

VIDEOEXAMPLE

THEMETHOD• 4 inch x 3 inch sheet Supralen 200-3W• Timed from placement until completely clear• Temperature measurements taken with thermocouple

• Temperatures• 300 °F, 350 °F, 400 °F

• Bake Method• Radiant heat, convective heat• Repeat 2x

• Minor temperature variations result in large measured time differences

THERESULTS

THECONCLUSION• Values calculated in MatLab were accurate to within 7% on average• Generally more accurate for convective heating• Convection decreased prep time by 15% when compared to pure radiant heat• Convective heat plays less of a role as oven temperature rises

Areas for improvement and more accurate measurements• Increase contact surface between blank and silicone• More consistent oven temperature• Accuracy of temperature readings• Known material properties• Take into account shape factors, directional radiative properties