# Thermodynamics Mech Expert

> Expert-level engineering thermodynamics covering laws of thermodynamics, thermodynamic cycles, steam power plants, refrigeration, gas dynamics, and combustion.

- Skill: `luokai0/thermodynamics-mech-expert` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add luokai0/thermodynamics-mech-expert`
- Raw SKILL.md: https://api.skillmd.com/api/skills/luokai0/thermodynamics-mech-expert/raw
- Safety review: pending (external: skill-scanner PASS, skillspector PASS)
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: luokai0 (https://skillmd.com/u/luokai0)
- Updated: 2026-09-08
- Page: https://skillmd.com/skills/luokai0/thermodynamics-mech-expert

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# Thermodynamics Mechanical Expert

## Before Starting
1. Which system type? (closed, open, steady-flow)
2. Which cycle? (Rankine, Brayton, Otto, Diesel, refrigeration)
3. Ideal or real with irreversibilities?

## Core Expertise Areas

### Laws of Thermodynamics
First law: energy is conserved, delta U = Q minus W for closed system.
Second law: entropy of universe increases for irreversible processes.
Entropy: ds = dQ_rev over T, measure of irreversibility.
Exergy: maximum useful work from system brought to equilibrium with environment.

### Power Cycles
Rankine cycle: steam power plant, boiler, turbine, condenser, pump.
Rankine efficiency: improved by superheat, reheat, and regeneration.
Brayton cycle: gas turbine, compressor, combustor, turbine.
Brayton efficiency: eta = 1 minus 1 over r_p to the power k-1 over k.
Combined cycle: gas turbine exhaust heats steam Rankine, 60% efficiency possible.

### Refrigeration
Vapor compression: compressor, condenser, expansion valve, evaporator.
COP: coefficient of performance, QL over W_net for refrigerator.
Heat pump COP: QH over W_net, always greater than refrigerator COP by one.
Carnot COP: maximum possible COP for given temperature limits.

### Gas Dynamics
Mach number: M = V over speed of sound, speed of sound = sqrt of gamma R T.
Isentropic relations: T2 over T1 = P2 over P1 to the k-1 over k power.
Normal shock: supersonic to subsonic, sudden pressure rise, entropy increase.
Nozzle flow: converging accelerates to M=1 at throat, diverging to supersonic.

## Best Practices
- Sketch system and identify boundary before applying first law
- Distinguish heat and work sign conventions carefully
- Use property tables for accurate steam and refrigerant properties
- Check second law consistency of calculated processes

## Common Pitfalls
| Pitfall | Fix |
|---|---|
| Sign convention errors | Define positive Q in and positive W out at start |
| Using ideal gas for steam | Use steam tables for accurate properties |
| Ignoring pump work in Rankine | Include pump work even though small compared to turbine |
| Adiabatic assumption for non-insulated system | Only apply adiabatic if process is fast or well-insulated |

## Related Skills
- heat-transfer-expert
- fluid-mechanics-expert
- physics/thermodynamics-expert