# Entropyk CLI

Command-line interface for batch thermodynamic simulations.

## Installation

```bash
cargo build --release -p entropyk-cli
```

## Usage

```bash
# Single simulation
./target/release/entropyk-cli run config.json -o result.json

# Batch processing
./target/release/entropyk-cli batch ./scenarios/ --parallel 4

# Validate configuration
./target/release/entropyk-cli validate config.json

# Help
./target/release/entropyk-cli --help
```

## Configuration Format

### Complete Chiller Example (R410A + Water)

```json
{
  "name": "Chiller eau glacée R410A",
  "fluid": "R410A",
  
  "circuits": [
    {
      "id": 0,
      "components": [
        {
          "type": "Compressor",
          "name": "comp",
          "fluid": "R410A",
          "speed_rpm": 2900,
          "displacement_m3": 0.000030,
          "efficiency": 0.85,
          "m1": 0.85, "m2": 2.5,
          "m3": 500, "m4": 1500, "m5": -2.5, "m6": 1.8
        },
        {
          "type": "HeatExchanger",
          "name": "condenser",
          "ua": 5000,
          "hot_fluid": "R410A",
          "hot_t_inlet_c": 45,
          "hot_pressure_bar": 24,
          "hot_mass_flow_kg_s": 0.05,
          "cold_fluid": "Water",
          "cold_t_inlet_c": 30,
          "cold_pressure_bar": 1,
          "cold_mass_flow_kg_s": 0.4
        },
        {
          "type": "ExpansionValve",
          "name": "exv",
          "fluid": "R410A",
          "opening": 1.0
        },
        {
          "type": "Evaporator",
          "name": "evaporator",
          "ua": 6000,
          "t_sat_k": 275.15,
          "superheat_k": 5
        }
      ],
      "edges": [
        { "from": "comp:outlet", "to": "condenser:inlet" },
        { "from": "condenser:outlet", "to": "exv:inlet" },
        { "from": "exv:outlet", "to": "evaporator:inlet" },
        { "from": "evaporator:outlet", "to": "comp:inlet" }
      ]
    },
    {
      "id": 1,
      "components": [
        { "type": "Pump", "name": "pump" },
        { "type": "Placeholder", "name": "load", "n_equations": 0 }
      ],
      "edges": [
        { "from": "pump:outlet", "to": "load:inlet" },
        { "from": "load:outlet", "to": "pump:inlet" }
      ]
    }
  ],
  
  "thermal_couplings": [
    {
      "hot_circuit": 0,
      "cold_circuit": 1,
      "ua": 6000,
      "efficiency": 0.95
    }
  ],
  
  "solver": {
    "strategy": "fallback",
    "max_iterations": 100,
    "tolerance": 1e-6
  }
}
```

## Component Types

| Type | Required Parameters | Optional Parameters |
|------|---------------------|---------------------|
| `Compressor` | `fluid`, `speed_rpm`, `displacement_m3` | `efficiency`, `m1-m10` (AHRI 540) |
| `HeatExchanger` | `ua`, `hot_fluid`, `cold_fluid`, `hot_t_inlet_c`, `cold_t_inlet_c` | `hot_pressure_bar`, `cold_pressure_bar`, `hot_mass_flow_kg_s`, `cold_mass_flow_kg_s` |
| `Condenser` | `ua` | `t_sat_k` |
| `CondenserCoil` | `ua` | `t_sat_k` |
| `Evaporator` | `ua` | `t_sat_k`, `superheat_k` |
| `EvaporatorCoil` | `ua` | `t_sat_k`, `superheat_k` |
| `ExpansionValve` | `fluid` | `opening` |
| `Pump` | - | `name` |
| `Placeholder` | `name` | `n_equations` |

## Thermal Couplings

Thermal couplings define heat transfer between circuits:

```json
{
  "hot_circuit": 0,
  "cold_circuit": 1,
  "ua": 5000,
  "efficiency": 0.95
}
```

- `hot_circuit`: Circuit ID providing heat
- `cold_circuit`: Circuit ID receiving heat
- `ua`: Thermal conductance (W/K)
- `efficiency`: Heat exchanger efficiency (0.0-1.0)

## Solver Strategies

| Strategy | Description |
|----------|-------------|
| `newton` | Newton-Raphson solver |
| `picard` | Sequential substitution (Picard iteration) |
| `fallback` | Picard → Newton fallback (recommended) |

## Exit Codes

| Code | Meaning |
|------|---------|
| 0 | Success |
| 1 | Simulation error |
| 2 | Configuration error |
| 3 | I/O error |

## Examples

See `crates/cli/examples/` for complete configuration examples:

- `chiller_r410a_full.json` - Water chiller with R410A
- `heat_pump_r410a.json` - Air-to-water heat pump
- `simple_cycle.json` - Simple heat exchanger cycle