Shown below is a cut-away of a Dewar flask designed to slow down all forms of he

Question

Shown below is a cut-away of a Dewar flask designed to slow down all forms of heat transfer. Pick a few of the labeled features and explain how each helps reduce heat transter. You do NOT need to explain every feature. Your goal is to explain enough to demonstrate an understanding of the three different heat transfer mechanisms discussed in this unit. (10 pts) 3. Glass walls with silvered surfaces Rubber stopper- Air layer Spring centering device Container RL Hot or cold liquid Vacuum Rubber support

Explanation / Answer

Basically there are 3 modes of haet transfer. They are

1) Conduction

2) Convection and

3) Radiation

Conduction is a phenomenon in which the heat transfer takes place in solid. About 70% of heat is transfered through free electrons and 30% of heat is transfered through lattice vibrations.

Convection is a phenomenon in which the heat transfer takes place through fluids. free and forced convection are the sub types in convection.

Radiation is a phenomenon in which the heat transfer takes place through no medium like vaccum. heat is transfered through electromagnetic waves.

So, by observing all the above definitions it is clear to explain the heat transfer process in the shown diagram

Rubber Stopper - The heat is transfered from hot/ cold surface fluid to rubber stopper through convention process.

Vaccum - No medium is present in the vaccum. So radiative heat transfer takes place from hot fluid to container.

Remaining all rubber support, glass walls, spring centering devices are solids. So the heat is transfered to outside throug conduction.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.