Simulation with Flux
Flux is an AI hardware engineer. It simulates circuits, routed boards, air and liquid flow, heat transfer, and battery cells, and analyzes mechanical parts and moving systems.
What you can simulate
Circuits: Run SPICE simulations on a project schematic or a circuit you describe.
Electromagnetic and RF behavior: Analyze routed traces and pairs for impedance, S-parameters, crosstalk, time-domain response, and eye diagrams. Simulate antenna feeds and review radiation patterns, gain, efficiency, and near-field maps.
PCB temperature: Calculate board temperatures from operating conditions or component powers, then review a summary heat map.
Air and liquid flow: Simulate air flow and temperature inside devices, enclosures, and around boards. Analyze natural or forced convection with vents, fans, and heatsinks, liquid cooling and pressure drop in channels, and drag around a product.
Power, batteries, and motors: Calculate power budgets for each rail, battery run time and C-rate, and motor and gearbox sizes. Run a detailed electrochemical cell model with the pack equations to get voltage under load, run time, and heat for a load profile.
Mechanical parts and assemblies: Analyze stress, deflection, heat conduction, fit, and tool access. Calculate mass, center of mass, inertia, and cross-section properties.
Robots and aircraft: Check robot reach, self-collision, and joint loads. Simulate drone and aircraft flight.
Circuit simulation
Ask Flux to run a SPICE simulation on the schematic in your project or on a circuit you describe. Give the component values and source conditions. Specify a frequency range for an AC or DC sweep, or a time interval for a transient run. Flux returns operating-point values, sweeps, waveforms, and plots for voltage, current, gain, ripple, and frequency response.
Example prompt:
Electromagnetic and RF simulation
Ask Flux to analyze routed copper on your board. Name the net or differential pair, the frequency range, and the result you need. You can review S-parameters such as S11 and S21, impedance, crosstalk, time-domain reflectometry (TDR), eye diagrams, and field maps.
For an antenna, ask Flux to analyze the routed feed and antenna net. You can review gain, efficiency, radiation pattern, input impedance, and near-field maps.
You can set impedance targets and stackup rules before you route. Give Flux the number of layers, board material, interface requirements, and target impedance. Ask it to define the layer roles and trace rules. After routing, ask Flux to measure routed impedance and compare it with the target.
For a routed via transition, ask Flux to report its S-parameters as part of the board analysis.
You can also upload S-parameter files (Touchstone .s1p, .s2p, .s4p) from a measurement or a vendor. Ask Flux to plot them, convert them to impedance or time-domain response, de-embed fixtures, or compare them with the simulated board.
For a wire antenna, such as a dipole, monopole, or helix, give Flux the dimensions and frequency. Flux simulates the input impedance, gain, and radiation pattern.
Example prompts:
PCB thermal analysis
Tell Flux the board's operating conditions, such as input voltage and load currents, or provide the dissipated power for each component. Flux can calculate component powers from operating conditions and datasheet values. You get component temperatures and a summary heat map.
Example prompt:
Power, battery, and motor analysis
Ask Flux to calculate a power budget for each rail. Give the load currents and operating modes, or let Flux read them from the datasheets. Flux sizes regulators, power paths, and trace widths from the budget.
For a battery pack, give the load profile and the cell type. Flux calculates the voltage under load, current, C-rate, run time, and heat.
For a battery check, Flux can run a detailed electrochemical cell model in addition to the pack equations to report cell voltage under load, run time, and heat for the load profile.
For a motor and gearbox, give the output torque and speed. Flux sizes the motor and gear ratio, and checks current, voltage, heat, and the motor driver rating.
Example prompts:
Mechanical analysis
Ask Flux to analyze a placed part. Provide its material, loads, and support conditions. For heat conduction, provide the heat input and ambient temperature. You get stress, deflection, or temperature values with units and locations.
Flux also analyzes beams and frames, and calculates cross-section properties such as area, moment of inertia, and section modulus. It checks fit, clearance, and swept envelopes of moving parts, and tool access for assembly.
Ask Flux for the mass, center of mass, and inertia of a part or a full assembly. Flux uses material values for custom parts and datasheet values for bought parts. See Mechanical Design with Flux for mechanical models and assemblies.
For a robot, describe its links, joints, actuators, payload, and poses. Flux creates a robot description file. Ask Flux to check reach, self-collision, joint or wheel loads, and motor sizing across poses, or to simulate the robot's motion with physics. This works for arms, grippers, pan-tilt heads, wheeled bases, and legged robots.
For a drone or aircraft, provide its mass, inertia, motors, propellers, battery, and flight conditions. Ask Flux to simulate hover, forward flight, climb, endurance, or response to a gust. Flux can also write the flight controller settings for the sized drone, such as the frame, motor map, and battery and failsafe limits.
Example prompts:
Air flow and liquid cooling simulation
Simulate air flow and heat transfer inside a device or enclosure, around a board, or around a product. Include vents, fans, or heatsinks to analyze natural or forced convection. For liquid cooling, describe the cold plate or channel and its flow conditions.
Give Flux the geometry, fluid and solid regions, boundary conditions, heat loads, and materials. Results include peak and outlet temperatures, flow rates, and pressure drops with units and locations. The report lists the geometry, fluid and solid regions, boundary conditions, heat loads, and materials used for the simulation.
Example prompts:
How to read and compare results
Check the axes, units, and operating conditions in each result. Review circuit and electromagnetic plots, PCB component temperatures and heat maps, and the values and locations in mechanical reports.
To compare a design change, run the same analysis again with the same circuit values, frequencies, board conditions, loads, and supports. Ask Flux to compare the results and explain which values changed.