Evaluate RPL Engine Workbench in 15 minutes.

Steps

1. Confirm your Mac. Apple menu > About This Mac: the chip line should say Apple M1, M2, M3, or M4.
2. Download and open the app. Get the disk image from the Download page, verify the SHA-256 if you wish (it is printed there), and drag the app to Applications. The build is signed by Rocket Propulsion Laboratory LLC and notarized by Apple, so it opens without security overrides.
3. Start trial mode. Launch the app. The trial starts automatically — no license key, no account.
4. Look at the default case. The project that opens is the built-in reference case: an NTO/Aerozine50 pressure-fed engine in the class of the Apollo Lunar Module Ascent Engine. Confirm the inputs: O/F 1.6, chamber pressure 841,160 Pa, expansion ratio 45.6, target thrust 15,568 N.
5. Solve it. Press Solve. Expect vacuum Isp 308.0 s, c* 1,616.6 m/s, chamber temperature 3,120 K, total mass flow 5.155 kg/s — and expect warnings: at the default sea-level ambient pressure this vacuum nozzle is severely overexpanded, and the solver says so explicitly rather than hiding it. That warning behavior is part of what you are evaluating.
6. Solve the flight condition. Set Ambient pressure to 0 Pa and Solve again. The overexpansion warnings clear and the vacuum numbers stand. NASA TN D-7400 Table I reports 309.7 s; this case produces 307.97 s, a −0.56% reference-case difference.
7. Read the solve summary. Check the convergence status, the thermochemistry provenance line (embedded CEA-referenced tables by default; if the optional RocketCEA backend is not installed, the solver tells you it fell back — it never switches silently), and the remaining warnings.
8. Review injector and nozzle results. Inspect the injector sizing outputs and the nozzle geometry: throat diameter 111.86 mm, exit diameter 755.35 mm. The same solved state drives both.
9. Export the report. Export the PDF report from the Report section. In trial mode it is watermarked; the content is the licensed report. Compare it against the report in the reference project package, which was exported by this same build.
10. Run the Flowfield preview. Open Flowfield Studio and run the steady preview for the solved case. The trial allows one steady run per launch at preview mesh limits — enough to see the nozzle flow structure and the provenance labeling. Transient playback, VTK export, and full mesh limits are paid features.
11. Decide by use, not by features. Both paid licenses unlock the same complete application. One named user doing personal, educational, academic, hobby, or other noncommercial work — including an individual member of a university team — uses the Personal license, $199/year; work for a company, customer, or employer uses the Business license, $799/year. Licenses may not be shared. Your license key activates the app you just installed — no new download.

Expected result

Your solved numbers match the published reference project to the precision shown, you have seen how convergence, provenance, and warnings are reported, and you have a watermarked report in hand.

What the trial does not do

• It cannot save projects or reusable data to disk — work is in-session only.
• DXF and VTK export are locked; PDF reports are watermarked.
• Flowfield is steady preview only: one run per launch, reduced mesh limits, no transient playback.
• The trial is time-limited (30 days).

Everything above unlocks with either paid license; licensing does not change the solver. If a step behaves differently on your machine than described here, that is exactly the kind of thing we want to hear about: support@rocketpropulsionlab.net.