Simulation Controls & Top Bar

The top of the editor has two rows. The upper row is branding, menus, the project name, version, theme, and your account. The lower row is the simulation control deck: EPS / MOC, Start / Reset, the clock and duration, and the speed slider.

Play, pause, reset, duration, and solver mode live here. Solver settings, reports, and scenario comparison live on the Simulation menu.

Project name

The project name sits to the right of the File / Edit / Data / Simulation / Help menus. It shows which model you are in. After Ctrl+S, the name flashes green to confirm the save.

Playback

These controls run and rewind the physics engine:

• Start / Pause / Resume: Starts the solver. Click again to pause and hold the current state (tank levels, battery charge, valve positions, and similar).
• Fast Run (No Visuals): Open the chevron on Start and choose this to finish the duration without canvas animation. Use it when you want results and reports quickly.
• Reset: Stops the engine and returns the clock and component states to their initial conditions. You must Reset before you can add components, switch EPS / MOC, or change some settings.

Clock and duration

The time pill sits next to playback. It shows the simulation day (D1), the clock time, and the run duration.

• Start time: Click the clock (12:00:00 by default) and type a new daily start (hours:minutes:seconds). This is the time of day the run begins, not the duration.
• Duration number: Click the number (for example 24) and type how long the run should last before it stops on its own.
• Duration unit: Click the unit next to that number to change what the duration input means:
• h — hours (EPS). Click to switch to days.
• d — days (EPS). Click to switch back to hours. The number converts (24 h ↔ 1 d).
• min — minutes (MOC only). The unit is locked to minutes in surge mode (maximum 360 minutes / 6 hours).

Switch EPS / MOC first if you need minutes vs hours or days. You cannot edit the clock or duration while a run is locked — click Reset first.

Simulation mode

The EPS and MOC pills choose the physics engine. The active pill is filled blue. This is not a dropdown.

• EPS (Extended Period Simulation): Steady-state hydraulics over hours or days. Use it for tank cycles, energy cost, and daily deliveries.
• MOC (Method of Characteristics): Millisecond-resolution surge / water hammer (valve closures, pump trips). Duration is in minutes.

MOC is a premium solver. If the project does not have access, the MOC pill will not stay selected. Switch modes before you open mode-specific commands on the Simulation menu. Glossary: EPS, MOC.

You cannot change mode while a run is locked — click Reset first.

Speed slider

For a 24-hour EPS run you do not wait 24 hours of wall clock.

• Speed slider: Drag to change how fast simulation time advances, from near real-time up to a fast-forward.
• Rate display: The blue pill to the right of the slider shows the current rate (for example 1 min/s).

[!NOTE] In MOC, the engine steps at a very small timestep (often 0.01 s or finer) so pressure waves stay accurate. The slider has less effect; the solver favors correctness over wall-clock speed.

Scenarios

Scenario comparison is not on this bar. Open Simulation → Scenarios... to create variants, record parameter overrides, and run them. See The Simulation Menu — Scenarios.

Version, theme, and account

On the far right of the upper row:

• Version: The build you are running (for example R-THYM v.1.000).
• Theme toggle: Sun / moon control for light and dark editor chrome. Full theme packs are still under Edit → Themes.
• Account: When you are signed in, the avatar opens account settings.

Fullscreen is on File → Fullscreen Mode, not on this bar. It hides the site header so the canvas uses more of the screen.