Sketch Heat Support

What is Sketch Heat?

Sketch Heat is an educational tool for learning heat transfer and the finite element method from simple sketches. Draw a part and its holes, mark where it is heated and cooled, and pick a material. Then see its temperature and where the heat flows in two dimensions, how fast it warms up or cools down, how much heat a fin, a radiator or a layer of insulation moves, and where a melt front is. It runs on iPhone and iPad with iOS or iPadOS 16.4 or later, in English.

Which analyses does it have?

Steady, over time, melting and freezing, and diffusion. Each works on a plate of a set thickness (a plane model), on the section of a long part (per unit depth) and on a round part (axisymmetric). Radiation to the surroundings works in all three; radiation between surfaces works in per-unit-depth models.

What is free, and what does Sketch Heat Pro add?

Free: open, run and explore every built-in example in every analysis, and draw your own outline and holes in a plate of aluminum or copper, with a hot edge and a cooled edge, in steady heat at the Coarse or Medium mesh. Projects, files, units, the help and the sample paper drawing are free too. Sketch Heat Pro adds:

• Every condition: heat flux, heat sources, radiation, fluid streams, contact and symmetry, and probes.
• Every material, and your own materials.
• Heat over time, melting and freezing, and diffusion.
• Convection worked out from the situation: still or moving air, water or oil.
• Fine meshes for more detail.
• Edit the examples.
• Import your own paper drawings from a photo.
• Reports with the model settings and probe readings.

How much does Sketch Heat Pro cost?

In the United States, US$4.99 per month with a 7-day free trial, or US$49.99 per year with a 14-day free trial. Prices differ in other countries, and the free trial is for eligible accounts only. The app shows the price for your country before you confirm.

How do I turn on Sketch Heat Pro on another iPhone or iPad?

Sign in with the same Apple Account, open Menu > Sketch Heat Pro, and tap Restore purchases. Restore purchases is also in Menu > About Sketch Heat.

How do I cancel?

Open Settings > your name > Subscriptions > Sketch Heat Pro, and cancel. Subscribers can also use Manage subscription in Menu > About Sketch Heat. To avoid the next charge, cancel at least 24 hours before the free trial or the current period ends. Deleting the app does not cancel the subscription.

How do I get a refund?

Apple handles all payments, so refunds are requested from Apple at https://reportaproblem.apple.com. We cannot issue refunds.

What happens when my subscription ends?

Nothing you made is deleted. All your sketches and projects still open and run. Changing a design beyond the free features needs Sketch Heat Pro again.

The app says the subscription could not be checked.

Connect to the internet and try again. Sketch Heat Pro stays active without a connection, and a failed check never turns it off.

Where are my projects stored, and how do I move them to another device?

Projects are saved on your device and are included in iCloud or computer backups of the device. They are not shown in the Files app, and deleting the app deletes them. To keep a copy or move a project, use Menu > Projects and files > Save as a file. It saves a Sketch Heat file (.sketchheat.json) to Files, Mail, AirDrop, or another place you choose. On the other device, open that file with Sketch Heat from Files or Mail, or use Menu > Open a file.

How do I delete my data?

Delete sketches and projects in Menu > Projects and files, or delete the app to remove everything stored in it. The app never uploads your sketches or pictures. The Privacy Policy says how to ask us to delete any other information.

Does Sketch Heat work offline?

Yes. Drawing and the calculation run on your device and work without a connection. Buying and restoring a subscription need a connection.

Can I use inches and degrees Fahrenheit?

Yes. Setup > View > Units switches every value you type and read, the probes, the charts and the report between SI (mm, W, °C) and US customary units (in, BTU/h, °F). Files always store SI, so a sketch reads the same in either.

Where do the material values come from?

From published sources and makers’ data sheets, each named in the app’s material list (Setup > Materials), with the temperature and condition its source gives. They are typical values; real parts vary with the grade, the supplier and the manufacturing process, 3D-printed parts especially. A value with no checked source shows as “not set”. You can copy a material and enter your own values.

How do I put a heat source or a probe at a single point?

Choose the Line tool and the part’s role, then tap the point twice, or tap it once and press Finish. A Heat source, a Probe or a Guide can sit at a single point, such as a small chip. A Temperature needs a line or an area. The temperature right at a point heat source depends on the mesh (see the next answer).

Why does the temperature at a point heat source keep rising when I choose a finer mesh?

At a point heat source the temperature is not finite in theory, and neither is the heat flux at a sharp inside corner, so the values there depend on the mesh. The heat totals do not. Read the temperature a little away from the point, or draw the source as a small area.

Can I draw with Apple Pencil?

Yes. Once you use Apple Pencil, only Apple Pencil draws, and your fingers pan and zoom. To draw with a finger again, turn off Menu > Draw with Apple Pencil only.

How accurate are the results?

Sketch Heat is for education and learning only. Its results are estimates from a simplified two-dimensional model, verified against published exact solutions and benchmark cases but not validated against measurements or tested in real-world scenarios. Do not use them to design, rate, or approve any real part or building, or for safety, medical, engineering, or compliance decisions. You use them at your own risk; to the extent the law allows, Journey On is not responsible for decisions based on them. The Sketch Heat Terms of Use list the model’s limits and the benchmark cases.

What does the app do with my information?

Your sketches, pictures, and results stay on your device; the app never uploads them. The app has no account and no ads, and it does not track you. The Privacy Policy has the details.