ME 5: Heat Transfer

Proof required

Link the public repo with selected exercises from chapters 1, 2 and 4 of Lienhard's textbook and the 2.051 Quiz 1 review problems written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• Each problem draws the thermal-resistance network before solving it.
• Fin answers check the Biot number and the fin efficiency.
• Answers match the solutions manual, and misses are reworked.

Common mistakes

• Answers copied from a solution with no working.
• Missing units, or a free-body diagram or sign convention left out.

Powstik Guide

A public write-up of selected exercises from chapters 1, 2 and 4 of Lienhard's textbook and the 2.051 Quiz 1 review problems, with the self-check shown.

Steps

1. Study the linked course material.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows the subject to check it.

README
ME 5: Heat Transfer, unit 1: Conduction: steady state, thermal resistance and fins
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• Each problem draws the thermal-resistance network before solving it.
• Fin answers check the Biot number and the fin efficiency.
• Answers match the solutions manual, and misses are reworked.
• Is the engineering right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with selected exercises from chapters 5–8 of Lienhard's textbook and the 2.051 Quiz 2 review problems written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• The lumped model is used only when Bi < 0.1, and that is shown.
• Each convection coefficient comes from a correlation valid for its Reynolds or Rayleigh number.
• Answers match the solutions manual, and misses are reworked.

Common mistakes

• Answers copied from a solution with no working.
• Missing units, or a free-body diagram or sign convention left out.

Powstik Guide

A public write-up of selected exercises from chapters 5–8 of Lienhard's textbook and the 2.051 Quiz 2 review problems, with the self-check shown.

Steps

1. Study the linked course material.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows the subject to check it.

README
ME 5: Heat Transfer, unit 2: Transient conduction and convection
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• The lumped model is used only when Bi < 0.1, and that is shown.
• Each convection coefficient comes from a correlation valid for its Reynolds or Rayleigh number.
• Answers match the solutions manual, and misses are reworked.
• Is the engineering right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with selected exercises from chapters 3 and 10 of Lienhard's textbook written up (a typeset PDF, LaTeX source or notebook), and show the self-check: which answers matched and how you fixed the ones that did not.

What gets checked

• Heat-exchanger problems state which method (LMTD or ε–NTU) and why.
• Radiation exchange uses view factors with the reciprocity rule checked.
• Answers match the solutions manual, and misses are reworked.

Common mistakes

• Answers copied from a solution with no working.
• Missing units, or a free-body diagram or sign convention left out.

Powstik Guide

A public write-up of selected exercises from chapters 3 and 10 of Lienhard's textbook, with the self-check shown.

Steps

1. Study the linked course material.
2. Solve the problems on your own first.
3. Check them against the self-check and rework the misses.
4. Typeset the write-up (LaTeX or a notebook) in a public repo.
5. Ask someone who knows the subject to check it.

README
ME 5: Heat Transfer, unit 3: Heat exchangers and radiation
Problems:
Self-check result (matched / reworked):
What I got wrong first and why:

What gets sent back

• No working shown.
• The self-check result is missing.

Resources

What a verifier looks for

• Heat-exchanger problems state which method (LMTD or ε–NTU) and why.
• Radiation exchange uses view factors with the reciprocity rule checked.
• Answers match the solutions manual, and misses are reworked.
• Is the engineering right, not just the final number?

You'll sign in first, then come straight back here.

Proof required

Link the public repo with the code or model files, the one command that reruns it, the convergence (mesh or step-size) study and the hand-calculation check, and a README that says how to rerun it and what limits the result.

What gets checked

• The grid and time-step studies show the answer converging, with the stability limit stated.
• The table compares simulation, lumped model and one-term solution at three times with Fo > 0.2, for both cases, and shows where the lumped model fails.
• The code reruns from the repo and reproduces every plot.

Common mistakes

• A result that nobody else can rerun from the repo.
• A table with no explanation of the gaps.

Powstik Guide

A finite-difference simulation of transient conduction in a slab or cylinder cooling in air, checked against the lumped model and the one-term analytical solution, in a public repo.

Steps

1. Write down what you expect before you start.
2. Write an explicit finite-difference solver in Python or Octave. State the stability limit: Fo = αΔt/Δx² ≤ 1/2 inside, and Fo(1 + hΔx/k) ≤ 1/2 at the cooled surface node. Run two cases: a metal block in air (Bi < 0.1), and a low-conductivity block such as wood or plastic, or a higher h (Bi > 1). Run a grid study (at least three grid sizes) and a time-step study until the centre's dimensionless temperature θ = (T − T∞)/(Tᵢ − T∞) changes by less than 1%. In a table, compare the result with the lumped-capacitance answer and the one-term series from Lienhard's chapter 5 (valid for Fo > 0.2). Optionally, measure a mug of warm tap water cooling and fit h with the lumped model.
3. Fill the predicted-vs-measured (or hand-vs-simulated) table.
4. Explain every gap with a cause someone can check.
5. Write the README and ask someone who knows the subject to check it.

README
ME 5: Heat Transfer — Simulate a cooling block and check it two ways
What I expected:
How to rerun it:
Predicted vs measured:
Why they differ:
Safety: hand tools and eye protection only

What gets sent back

• No convergence study, or no hand calculation that checks it.
• Machine tools, welding, pressure vessels, combustion, or springs and flywheels storing dangerous energy without a trained supervisor.

Resources

What a verifier looks for

• The grid and time-step studies show the answer converging, with the stability limit stated.
• The table compares simulation, lumped model and one-term solution at three times with Fo > 0.2, for both cases, and shows where the lumped model fails.
• The code reruns from the repo and reproduces every plot.
• Check the engineering and the numbers, not just that it exists: do the units, the hand calculation and the table agree?
• Build photos show hand tools only and eye protection worn: no machine tools, welding, pressure vessels, combustion, or springs and flywheels storing dangerous energy (unless a trained supervisor and a proper workshop are shown).

You'll sign in first, then come straight back here.