Flowstead v3.2.0

Flowstead v3.2.0 (app version 3.2.0).

Compound and data tools, flowsheet tools, McCabe–Thiele and catalytic reactions

Compounds and data (Fluid package → Compound and data tools):

• A compound from its structure. Type a SMILES string, such as CCO or Cc1ccccc1, or count Joback's groups by hand. The engine then estimates the boiling point, critical constants, heat capacity and formation energies with DWSIM's Joback method. For n-hexane it matches Joback's published method exactly. Example 22 shows one in a flowsheet.
• Look a compound up on PubChem. A name or CAS number brings its structure from NCBI's PubChem (needs the internet). The properties are still the engine's estimates.
• VLE regression. Fit a pair's kij, or its NRTL or UNIQUAC parameters, to measured bubble points, see the deviations before and after, and use the fitted values in the fluid.
• Reaction finder. DWSIM's reaction finder suggests combustion, kinetic and catalytic reactions among your components, with their equilibria. Add any of them to the flowsheet. Its rates are literature values: check them before design use.
• Catalytic reactions. Langmuir–Hinshelwood rates per kg of catalyst, in a PFR or CSTR with a catalyst loading (and, in a PFR, a bed void fraction and optional particle size).

Flowsheet tools (⋮ → Tools):

• Check: everything that stops a solve or makes a result doubtful, in one list. Tap an item to open its object.
• Watch: results pinned on the canvas.
• Spreadsheet: formulas on solved results, such as =[K-100.power]+[K-200.power], with cells you can export to specifications.
• Scenarios: save cases, compare them side by side and restore one.
• Optimiser: minimise or maximise a result, or a sum of results, by moving up to six specifications within bounds, with constraints. For a two-stage compressor it finds the textbook interstage pressure.
• PID tuning: a step test in the dynamic run, a fitted process model, and SIMC, IMC, Ziegler–Nichols and Cohen–Coon settings, each one tap to use.
• McCabe–Thiele: a binary column stage by stage on the engine's equilibrium curve, with minimum stages and minimum reflux; the diagram draws both operating lines meeting on the q-line.
• Report: the whole case as Markdown to share.

Also:

• Column internals: the column sizing now rates its sieve trays. It gives the weir crest, tray pressure drop, downcomer backup and residence time, and the percentage of flood at the chosen diameter.
• Custom unit sets: save your own named sets in Settings → Units.
• Sample library: search and filter the examples in Help → Examples.
• Backups: a copy of each project is kept every 10 minutes of editing, and a deleted project can be recovered (Projects → ⋮ → Backups, or "Recover a deleted project").
• A changed kij now always takes effect: DWSIM's cubic packages kept an older kij matrix in some calculations.

Install: download flowstead-v3.2.0.apk on your Android phone (Android 8.0 or newer, 64-bit), open it and allow installing from this source.

Coming from a 0.x test build? Those were signed with the public debug key and this release is signed with the release key, so Android can't install it over them: export each project you want to keep (project menu → Export DWSIM file), uninstall the old app, install this one and import the files (Projects → Import DWSIM file). Data-sheet fields and line-sizing criteria are not part of a DWSIM file. Later releases install as updates.

Solves on the phone: DWSIM runs on the device (Settings → Engine → On this phone, the default); the first solve after starting the app takes a few seconds while DWSIM loads. A remote Flowstead engine (docs/engine-setup.md) is optional.

Release certificate SHA-256: d7883cfc24f1cb62db989086d69d217beed109b5b84164ff5394ad9e3e0bb921. flowstead-v3.2.0-mapping.txt de-obfuscates crash reports. Status and known limitations: docs/STATUS.md.

Commit: 98a9d84