Quick Mode

In-browser, sequential-modular simulation engine written in TypeScript. Runs entirely client-side — no backend, no auth, no network round-trip.

Source: opensource/src/

What it is

Quick mode is the default Jasper engine. It executes blocks one at a time in topological order, with Wegstein acceleration for recycle convergence. Designed for instant feedback during flowsheet construction, teaching, and screening studies.

Aspect	Detail
Architecture	Sequential modular, client-side
Latency	<100 ms (typical)
Offline	Yes
Property methods	Ideal, Peng-Robinson, NRTL
Recycle handling	Wegstein acceleration, tol 1e-4
DOF check	No
Components	70+ (DIPPR / NIST validated)
License	MIT

Thermodynamics

Three property packages are selectable per project:

Method	K-value model	Best for
Ideal	Raoult's Law	Ideal mixtures, low pressure
Peng-Robinson (PR)	Fugacity (phi-phi)	Hydrocarbons, gases, high pressure
NRTL	Activity coefficients (gamma-phi)	Polar / non-ideal liquids (ethanol-water, amines)

Underlying property calculations:

• Lee-Kesler vapor pressure — 1 – 3% error, boiling-point anchored
• Rackett liquid density
• Entropy with departure functions (used by isentropic equipment)
• Heat of reaction from heats of formation + Cp integration
• 70+ component database with DIPPR / NIST validated data
• ~20 NRTL BIP pairs for common systems

Unit operations

Unit op	Method
Flash / Separator	Rigorous VLE with property-package K-values
Distillation column	Fenske-Underwood-Gilliland shortcut
Reactors (RStoic, REquil, RGibbs, …)	Stoichiometric + heat of reaction, equilibrium
Compressor	Isentropic with entropy-based Newton iteration
Pump	Rackett liquid density for real power
Absorber / Stripper	Kremser equation (general, multi-solute)
Heater / Cooler	Rigorous enthalpy-based duty
Mixer / Splitter	Enthalpy balance with Newton T iteration
Valve	Isenthalpic throttling
Heat exchanger	Counter-current with effectiveness

Solver

Topological sort → detect tear streams → block-by-block solve
                              │
                              ▼
                      Wegstein acceleration
                          (tol 1e-4)
                              │
                              ▼
                          Converged

• Sequential modular block-by-block execution
• Topological sort with automatic tear stream detection
• Wegstein acceleration for recycle convergence (tolerance 1e-4)

Use this when

• Building or teaching a flowsheet — you want instant feedback as you wire blocks
• Your system is nearly ideal (light hydrocarbons, dilute aqueous mixtures)
• You need to work offline
• You're screening many design variants before committing to a rigorous solve

Switch to Rigorous (DWSIM) when

• The system is strongly non-ideal (azeotropes, electrolytes, polar solvents at high pressure)
• You need CSTR / PFR / Gibbs reactors (Quick supports shortcut reactors only)
• You need DWSIM's broader property-package coverage (UNIQUAC, UNIFAC, IAPWS steam, electrolytes)

For equation-oriented optimization, ask the Jasper agent in chat — it routes the request to IDAES + IPOPT under the hood. See Optimize mode.

Verification

The Quick engine ships with a 16-test parity suite:

npx tsx src/sim/thermo/__tests__/quickmode-parity.test.ts

Covers Lee-Kesler Pvap (water, ethanol, benzene, methane within 2%), PR flash (propane-butane two-phase), NRTL activity (ethanol-water gamma > 5), isentropic compressor (N₂, 0.1% error vs textbook), benzene-toluene FUG distillation (99% purity), water-gas-shift reactor heat of reaction, recycle convergence with Wegstein (3 iterations), and Kremser CO₂ absorption.

Limitations

• No degrees-of-freedom check — under- or over-specified flowsheets fail silently or with confusing errors
• No simultaneous equation solve — tightly coupled recycles can be slow or fail to converge
• No optimization
• ~20 NRTL BIPs only — other binaries fall back to estimated values
• No solid phases