DF Studio v0.2.0

Cycle diagram

• Component library in collapsible groups with monochrome icons that follow
  the theme: turbines, compressors and fans, pumps, heat exchangers, HRSG
  (economizer, evaporator, superheater, duct burner, SCR, duct, stack,
  fan), condensers and cooling (water-cooled condenser, air-cooled
  condenser, cooler, cooling tower), valves and piping, sources and sinks,
  electrical, annotations. The Components tab uses the same groups.
• Turbine and compressor connection points at five stages on each tilted
  casing line (diagrams saved by 0.1 keep their points).
• Right sidebar with KPI and States tabs, and below them all the
  diagram settings (lock, stream labels, title, PDF export, fit view). The
  left sidebar keeps the palette, the templates and the selected
  component's or stream's settings.
• The state table adds mass flow, entropy, vapour quality,
  superheating/subcooling degree, density, cp and the fluid, and has a
  Copy table (TSV) button.
• The PDF report keeps the label style, state numbering, label size and
  positions, stream colours and the cross unit legend of the canvas, and
  uses the same state table.

Solver

• Automatic starting values: 25 °C for temperatures, 1 bar for pressures and
  0.5 for qualities instead of 1 in model units (1 K and 1 Pa in SI).
• Automatic bounds for variables used directly as property inputs
  (temperature above 0 K, pressure above 0, quality 0 to 1), which never
  exclude a valid solution.
• Warm start keeps the last converged value of each variable when a later
  solve fails, and starts from the solution saved in a .df project when it
  is opened.
• Equations > Initial values: guesses and bounds per variable with a unit
  picker, the value each variable started from and its source; saved in the
  project.

Plots

• Logarithmic axes are drawn as on log paper: decade lines and fainter
  lines at 2..9 times each decade (and 1.1, 1.2, ... when zoomed in), with
  labels at the decades.
• Export Python uses the SciencePlots style when installed, LaTeX text when
  LaTeX is available (labels escaped), a journal-column figure size, and
  minor grid lines on log axes.

Interface

• Monochrome icons, following the light or dark theme, on the entries of
  the File, Edit, Solve, Units, View and Help menus, with the keyboard
  shortcuts right-aligned.
• The toolbar's Solve button is hidden while Solve > Live solve while
  typing is on (F2 still solves).

Examples

• New recuperated Brayton example (air, recuperator by effectiveness, LMTD
  function).
• Every example sets the mass flow of each state (m[i] with Duplicate),
  so the cycle diagram shows the flow of every stream, and is commented to
  introduce the language and the cycle.
• The example projects include a solved parametric table, a goal seek or an
  optimisation and plots (property diagram, XY or 3D).

Verification

• Tests of the property pipeline against IAPWS-95 (Tables 7 and 8),
  IAPWS-IF97 (Tables 5 and 15), NIST-JANAF and exact thermodynamic
  identities in five unit systems; solver tests against closed-form
  solutions and a direct CoolProp calculation. See docs/VERIFICATION.md.
• examples/ees_crosscheck.dfs: a 199-equation model that runs unchanged in
  EES, for comparing the two programs.

Fixed

• The solver could report convergence at a spurious root created by
  clearing a denominator (for example an LMTD at dT1 = dT2, where the
  equation is 0/0), with an infinite residual. Such points are refused, the
  block is retried on the equations as written, and a solution whose
  residual cannot be evaluated is never reported as converged.
• Steam_IAPWS (EES) now maps to IAPWS-95 like Water, as in EES; it was
  read as IAPWS-IF97. R718 is accepted as water.
• converttemp(...) results were labelled and display-converted as model
  temperatures; they are plain numbers now.
• A rare crash ("double free or corruption") when several threads created
  CoolProp states at the same time, e.g. a parametric table or optimisation
  starting its workers: creating a state now has exclusive access to
  CoolProp. The states of a worker thread are released when it ends, so
  repeated studies no longer accumulate memory.

Downloads

System	File
Windows 10/11 (x64)	*-windows-x64-setup.exe (installer; all users or current user) or *-windows-x64-portable.zip
macOS 11+ (Apple silicon and Intel)	*-macos-universal.dmg (first launch: right-click > Open)
Linux (x86-64, glibc 2.38+, e.g. Ubuntu 24.04)	*-linux-x86_64.AppImage (chmod +x, then run)

SHA256SUMS.txt lists the checksums of all files.