dwsim-api-verification

What I do

• •Source Code Verification: I verify that classes, methods, and properties used in Enerflow.Worker actually exist in the local DWSIM source code (libs/dwsim_src).
• •Signature Checking: I ensure that the arguments passed to DWSIM methods match the function signatures found in the source.
• •Deprecation Guard: I actively check for deprecated or void methods (e.g., CalculateFlowsheet2) and suggest the correct alternatives (e.g., RequestCalculation).

When to use me

• •Coding: IMMEDIATELY BEFORE writing any code that calls into DWSIM.* namespaces.
• •Debugging: When a MethodNotFoundException or MissingMemberException occurs related to DWSIM.
• •Refactoring: When upgrading DWSIM versions or changing simulation logic.

How to Verify (The "Grep Check")

FIRST: Check the DWSIM_API_MAP.md file in the project root. It contains the pre-scanned, authoritative API context.

If the information is not in the map, use grep to find it in libs/dwsim_src.

1. Find the Class Definition

Do not guess where a class is. Find it.

# Example: Finding the Flowsheet class
grep -r "class Flowsheet" libs/dwsim_src/DWSIM.FlowsheetBase

2. Verify the Method Signature

Once you know the file, read it to check the method arguments.

# Example: Checking RequestCalculation arguments
grep -A 5 "public void RequestCalculation" libs/dwsim_src/path/to/Flowsheet.vb

3. Check for Enum Values

DWSIM uses many Enums (e.g., PropertyPackageType). Verify the exact spelling.

grep -r "Enum PropertyPackageType" libs/dwsim_src

Common DWSIM Pitfalls

1. Automation Class Selection

• •WRONG: DWSIM.Automation.Automation (Legacy, limited features)
• •CORRECT: DWSIM.Automation.Automation3 (Full-featured, use for tests and advanced automation)
• •Alias: using DWSIMAutomation = DWSIM.Automation.Automation3;

2. Calculation Methods

• •WRONG: var errors = Automation.CalculateFlowsheet2(flowsheet) (Automation3 returns void, not List<Exception>)
• •CORRECT: Automation.CalculateFlowsheet2(flowsheet); (Call without assignment)
• •Error Checking: Use flowsheet.Solved and flowsheet.ErrorMessage properties after calculation
• •Alternative: flowsheet.RequestCalculation(...) (For async/internal calculation)

3. MaterialStream Compound Handling

• •WRONG: Calling flowsheet.AddCompoundsToMaterialStream(stream) after AddObject(ObjectType.MaterialStream, ...)
• •CORRECT: Just use AddObject() - it already calls AddCompoundsToMaterialStream internally
• •Error: Double-calling causes ArgumentException: An item with the same key has already been added
• •Source: FlowsheetBase.vb:1297 shows AddCompoundsToMaterialStream(myCOMS) is called during AddObjectToSurface

4. Unit Operation Calculation Modes

• •Valve: Default CalcMode is DeltaP. To specify outlet pressure, set CalcMode = Valve.CalculationMode.OutletPressure before setting OutletPressure
• •Heater/Cooler: Set CalcMode to OutletTemperature, HeatAdded, etc. based on known specification
• •Compressor: Use CalculationMode.OutletPressure when specifying target pressure

5. Heat Duty Sign Convention

• •DWSIM Convention: Both Heater and Cooler report DeltaQ as positive magnitude
• •Cooler does NOT return negative values for heat removed
• •Validation: Check that cooler output temperature is lower than input, not the duty sign

6. Property Names Case Sensitivity

• •Observation: VB.NET origin means some properties are lowercase or inconsistent.
• •Example: IPhaseProperties.molarfraction (lowercase) instead of VaporFraction or MolarFraction.
• •Reference: Check docs/DWSIM_API/IPhaseProperties.cs for exact property names.

7. Thread Safety

• •Constraint: DWSIM Automation is single-threaded.
• •xUnit Config: Use xunit.runner.json with "parallelizeTestCollections": false and "maxParallelThreads": 1
• •Worker: Architecture handles this via ConcurrentMessageLimit = 1.