Changelog

This is the record of what has shipped in Fluid Network Studio, newest first. Dates are the day the change was released, and every entry is something you can go and use. Work that never reached you is not listed here.

The tool is developed continuously rather than in numbered releases, so entries are grouped by month and named for the capability they delivered. Solver changes are held to the same gate throughout: a change ships only once the verification suite passes, and any release that could move an existing result is gated on reproducing that result first.

One naming note. The product was called Hydraulic Network Studio until 4 July 2026, when it was renamed Fluid Network Studio because the solver had long since stopped being only about water. Older files, saved links and search results may still carry the old name. Everything still works.

August 2026

13 August 2026 - Nine more published verification cases

The verification page now publishes 31 cases, up from 22. The nine added were already in the test suite with a named published reference behind each one, and publishing them puts the reference, the method and the agreement in front of you rather than leaving them internal. Every build re-runs the full set.

13 August 2026 - Expert settings, so the Studio starts simple

Solver numerics and the CFD coupling controls are now behind an Expert toggle in the Model tab. The defaults are the right answer for nearly every network, and moving them out of the way means a first-time user is not asked to have an opinion about convergence tolerances. Turn Expert on and everything is exactly where it was. If a hidden value differs from the default, the panel says so rather than hiding a setting that is doing something.

13 August 2026 - A long-form guide to EPANET alternatives

A new guide covering the tools engineers actually move to when they outgrow EPANET, what each one is genuinely for, and where each one stops, including our own entry with the bias declared. The capability pages were deepened alongside it.

13 August 2026 - Faster homepage and per-page social cards

A lighter hero image on the homepage and a social preview card generated per page, so a shared calculator, worked example or guide now unfurls with its own title and description instead of the generic site card. The glossary gained cross-links to the pages that use each term.

13 August 2026 - Fixed: dialogs stealing focus mid-typing

A dialog opening no longer pulls the cursor out of the field you are typing in.

July 2026

24 July 2026 - The worked-example library reached 20

Six more worked examples were added, completing the set of 20 across incompressible, heat, gas and non-Newtonian networks. Every one opens straight into the Studio as a live network you can solve and edit, and each has a page showing the setup and the solved result. The glossary gained seven more terms at the same time, and the free calculators were deepened with reference tables and worked numbers.

18 July 2026 - Dark mode

An opt-in dark theme across the site and the Studio, with the theme toggle in the header. The canvas, the result colour scales and the charts were all re-checked in both themes rather than inverted and hoped for.

14 July 2026 - Fixed: the results dock would not resize

Dragging the results dock taller now works properly, with no arbitrary height cap.

13 July 2026 - Automatic velocity basis for fittings

A fitting between two different pipe sizes now resolves which bore its loss coefficient applies to, with smaller, larger or manual as the choice. Getting this wrong is a classic quiet error in minor-loss calculations, because K is meaningless without the velocity it refers to.

13 July 2026 - Studio handling fixes

Annotations are now included when you fit the view. The panel resize handles are visible instead of invisible. A multi-element selection survives align, distribute, rotate and nudge, so you can chain two operations without reselecting.

12 July 2026 - Full-screen results

A maximise control expands the results dock to fill the canvas area, with Solve and Colour by still reachable, and Escape restores it to the exact height you had before.

12 July 2026 - Drawing tools: rotate, align and distribute

Component symbols rotate in 45 degree steps, elbows auto-orient to the pipes they join, and a multi-element selection can be aligned or evenly distributed. Report and drawing capture now fits the view first, so an exported drawing is framed rather than cropped.

12 July 2026 - Time-series charts for time simulation

Velocity and tank fill percentage plot over the whole run in the Charts tab, so a transient result is something you read as a curve rather than by scrubbing to a timestep and squinting.

12 July 2026 - Disable any element

Every element carries a Disable checkbox now, generalising what was previously only available for pipes. The network prunes around the disabled part and tells you what it isolated, instead of refusing to solve.

11 July 2026 - Free became genuinely useful, and Advanced dropped to A$39

Pricing collapsed from three tiers to two. Free covers liquid analysis up to 100 elements, cloud save for up to 10 projects, EPANET import and side-by-side scenario comparison, with no trial clock. Advanced went from A$50 to A$39 a month, or A$390 a year, and carries gas, heat transfer, non-Newtonian flow, the CFD coupling export and every export format. The Basic tier is gone.

11 July 2026 - Drag and drop from the palette

Elements can be dragged from the palette and dropped where you want them, on a mouse or a touchscreen. Click to add still works exactly as before.

11 July 2026 - Studio layout consolidation

A rebuilt studio shell: a proper app bar and toolbar, a bottom results dock instead of a crowded side column, the inspector merged into Selection and Model tabs, a redesigned palette, and a command palette with a keyboard shortcuts sheet. The results dock then gained charts that fill it, results tables side by side, and difference maps for compressible-gas scenarios.

10 July 2026 - The verification page, rebuilt

Verification was rewritten around the control valves and new elements, with the cross-checks against EPANET and NASA's GFSSP examples named case by case, and an automated guard that fails the build if any quantitative claim in the site copy stops matching the code behind it.

9 July 2026 - Control valves

Non-return (check) valves, pressure-reducing valves, pressure-sustaining valves and flow-control valves, with a status-switching outer loop that settles which valves are active, throttling or fully open. Control valves survive an EPANET import and export with their control law intact, and a diagnostics panel explains a valve that will not settle rather than just failing to converge.

8 July 2026 - Pumps, fans and compressors became components

Machines are now placed as components with an explicit inlet and outlet, like a valve, instead of being drawn as a special kind of pipe. Pipe is the only link. Existing saved networks migrate automatically, and the migration was gated on reproducing the same solved result, so a network you saved before the change still gives the answer it gave before.

8 July 2026 - A much bigger component library

A fitting library with vendor-K entry tools, standard pipe dimension tables, machine templates with a duty-point wizard, orifice plates, sudden expansions and contractions, non-circular ducts with a hydraulic-diameter treatment, and a compressible orifice. This is the release that took the tool from "pipes and pumps" to something you can build a real plant line with.

5 July 2026 - Positioning corrected: the tool is not steady-state only

A copy sweep across the site, the terms and the machine-readable summaries, because several pages still said "steady-state only" months after the quasi-steady time-simulation mode shipped. The real fence, no water hammer or surge, no settling slurries, no water-quality tracking, is stated loudly instead.

4 July 2026 - Renamed to Fluid Network Studio

Hydraulic Network Studio became Fluid Network Studio, with a new logo and a new domain. The old name described a water tool, and the solver had handled gases, heat transfer and non-Newtonian fluids for a month by then.

4 July 2026 - Tablet layout

A responsive, read-first layout for tablets: the palette becomes a drawer, the panels reflow, and every touch target was audited rather than assumed.

3 July 2026 - Solve without an account

Anonymous visitors can build and solve a network up to an element cap. The account wall moved from Solve to Save, which is where it actually belongs, since you should be able to find out whether the tool works before signing up for anything.

3 July 2026 - Trust and reproducibility

The calculation report carries a real build-version stamp, so a printed result names the version that produced it. A reproducibility statement explains what stays fixed between runs, and the data-residency note now correctly names the Sydney region where accounts and projects are stored.

3 July 2026 - Real solver output on the homepage, and thumbnails on the examples

The homepage showcase is a genuine solved network rather than an illustration, and the example cards carry real network schematics instead of generic icons.

2 July 2026 - Free calculators

A free, ungated calculator hub: pipe pressure drop, Reynolds number, Darcy friction factor, pipe velocity, pump power, Hazen-Williams and insulated pipe heat loss, each one a single-topic page with a live widget. They run the same physics the full solver runs, asserted equal to it in the test suite, so a quick check here agrees with a full solve there. Each gained an input-reactive diagram, a standard pipe-size selector and SI or imperial switching within the same fortnight. Orifice plate K and rectangular-duct pressure drop followed on 10 July.

1 July 2026 - Results and postprocessing

The largest single release for reading results. Sortable, filterable results tables with a column picker, per-column units and conditional formatting. A query bar that highlights matching elements on the canvas. Named scenarios with difference maps between any two. A pump and fan chart with the system resistance curve, the best-efficiency point and the preferred operating region. User-set colour ranges with a lock so the legend stays constant across re-solves. Drawing export as PNG or SVG, multi-sheet Excel export, and a branded calculation report with your own logo and a section picker. The Results panel was then de-congested into popouts so all of it fits one screen.

1 July 2026 - Straight pipes, and View settings that stick

Pipes can be drawn straight instead of curved, for anyone who found the curves distracting, and View preferences now persist per user across projects instead of resetting on reload.

June 2026

30 June 2026 - EPANET .inp import and export

Open an existing EPANET model directly, free, and export back to .inp on Advanced. Elements that have no equivalent are flagged rather than silently dropped, so you know what did not come across. This is the shortest path in for anyone with years of existing models.

30 June 2026 - Hazen-Williams, fixed friction factor, and a public verification page

A head-loss method selector, so a network can be solved with Darcy-Weisbach, Hazen-Williams or a fixed friction factor, with per-pipe C or f values and an advisory when Hazen-Williams is used outside its valid range. The first public verification page shipped with it, at 11 cases across six fluid families, each against a named published reference.

29 June 2026 - Sign in with Google or Microsoft

Social sign-in, which also side-steps the confirmation email getting quarantined by corporate mail filters.

23 June 2026 - Temperature in the CFD coupling

The CFD coupling export exchanges temperature as well as pressure and mass flow when heat transfer is on, so a coupled run converges on a consistent thermal and hydraulic operating point rather than a hydraulic one with temperatures bolted on.

21 June 2026 - CFD coupling export for STAR-CCM+

Export a network as a self-contained STAR-CCM+ Java macro that runs the network solver as a live boundary condition inside a CFD solve, with the CFD solver driving. It carries a setup checklist generated for your network and runs a read-only preflight that checks your simulation and stops without changing anything if something is missing. The embedded solver is a validated port of the app's own, checked against its output on the pinned verification set. Full detail is on the CFD coupling page.

20 June 2026 - Time simulation

A quasi-steady time-domain mode: open atmospheric tanks that fill and drain, scheduled and triggered throttle valves, pump start and stop, and time-varying demand, with a timestep strip you can scrub. Fast transients and pressure waves are explicitly out of scope, and a gas transient is refused rather than approximated. Time simulation covers liquids and is included on every plan, free ones as well.

18 June 2026 - Share a network by link

A view-only share link for any saved network, with a rich preview when it is pasted into a chat or a post, so a colleague can look at a model without an account.

16 June 2026 - Editing batch

Bulk editing across a multi-pipe selection, a Clear results control, an annotation appearance editor with colour swatches, duplicate producing a detached copy you can drag onto new nodes, and a branded favicon.

14 June 2026 - The content programme

Application guides, a glossary, worked-example pages and a how-it-works reference, all statically generated and all free. Cookieless analytics shipped alongside, with no advertising cookies or third-party trackers anywhere on the site.

13 June 2026 - The marketing site moved to the root, the app to /studio

A routing change that gave the app its own address and the site its own front page, plus the about page and the first round of technical SEO work.

11 June 2026 - Subscription billing and plan gates

Stripe billing with monthly and annual options and a free trial, and in-app feature gates that match what each plan actually includes.

10 June 2026 - Professional editing and saving

A proper save model that distinguishes updating from Save As and warns about unsaved work. CAD-style marquee selection with crossing and window behaviour, multi-element editing, arithmetic in number fields, keyboard shortcuts, closing and detaching pipes, parallel pipe runs, configurable advisory limits with click-to-locate, and a drawing annotation layer.

6 June 2026 - Non-Newtonian fluids

Power-law and Bingham plastic fluids for homogeneous, non-settling slurries and process fluids, using the Metzner-Reed generalised Reynolds number with the Dodge-Metzner correlation, and Buckingham-Reiner with the Darby-Melson and Hanks methods. Each pipe reports its flow regime. Settling and heterogeneous slurries are permanently excluded, because a steady network solver has no business predicting deposition.

6 June 2026 - Pump duty and cavitation diagnostics

Hydraulic and shaft power from a fixed efficiency or an efficiency curve, the best-efficiency point, and a warning when the duty point sits too far from it or off the end of the curve. NPSH available is computed with the Antoine equation for vapour pressure, with a cavitation-risk flag when the suction margin is thin.

6 June 2026 - Print-ready calculation report

A calculation report generated entirely in your browser, collecting the network, the methods used and the results into a record you can print or save.

6 June 2026 - Real-gas density

Peng-Robinson compressibility for gas density, with a near-dome guard. Enthalpy stays ideal by design, so Joule-Thomson effects are zero and are not claimed.

6 June 2026 - Compressible gas, fans and compressors

A compressible-gas mode solving in absolute pressure with mass balances and varying density, using the exact isothermal pipe relation including the acceleration term. Fans carry a density-scaled pressure-rise curve with an operating-point chart, compressors are set-point machines reporting discharge temperature and shaft power, and boundaries can be entered as gauge or absolute. A thermal march followed within days, integrating friction, acceleration and wall heat along each pipe so a cooling gas line shows density rising and velocity falling, with Sutherland temperature-dependent viscosity through the march.

5 June 2026 - Heat transfer for liquids

Each pipe can lose or gain heat through an inner film using Gnielinski or Dittus-Boelter with a laminar fallback, through the wall and insulation as a composite-cylinder resistance, or through a direct U value. Streams mix by enthalpy at junctions and an energy balance runs on every solve.

4 June 2026 - The verified solver core

The foundation, built and verified before any interface work: a steady-state incompressible network solver using the global gradient algorithm of Todini and Pilati with Darcy-Weisbach head loss, the Churchill friction factor, fixed-K minor losses from a Crane TP-410 library and least-squares pump curves. It passed the full verification suite, including the classic three-reservoir problem and looped networks, with tight conservation residuals on every solve, and its incompressible results are cross-checked against EPANET.

What is next

The roadmap follows what people actually ask for, so if something above stops short of what you need, use Send feedback in the Studio's Help menu and say so. Two gaps we already name openly on the CFD coupling page: a Fluent version of the export, which is STAR-CCM+ only today, and temperature-dependent fluid properties in the coupled thermal model, which uses constant properties today. Neither has a date, and neither appears above, because nothing goes on this list before it ships.

Open the Studio and try any of it. Liquid analysis, the 20 built-in examples and the free calculators cost nothing.