An aerospace engineering team is modifying the solid metal thermal struts that connect a heat-generating electronics module to a cooling radiator. Match each proposed design modification with its specific physical effect on the rate of conductive heat transfer through the strut, assuming the temperature difference remains constant.
- Changing the strut material from stainless steel to copperSubstantially increases the rate of heat flow due to a higher intrinsic thermal conductivity.
- Using two identical struts in parallel instead of a single strutDoubles the rate of heat flow by doubling the total cross-sectional area available for conduction.
- Increasing the overall length of the strut by a factor of twoHalves the rate of heat flow by doubling the physical distance the thermal energy must travel.
- Machining a hollow core through the center of the strutDecreases the rate of heat flow by reducing the effective cross-sectional area of the solid material.
Answer
Changing to copper increases conductivity; using parallel struts doubles the area; increasing length halves the transfer rate; and machining a hollow core reduces the cross-sectional area.
The rate of conductive heat transfer through a solid object is determined by its material's thermal conductivity, the cross-sectional area perpendicular to the heat flow, and the length of the pathway. Adjusting these physical parameters directly alters the heat flow according to proportional relationships.
Step-by-Step Solution
Key Concept
Variables in Fourier's Law of Heat Conduction