Thermodynamics
Gas laws, heat transfer, entropy, and engine cycles
Psychrometric Chart
Moist-air HVAC chart: dry-bulb, RH, humidity ratio, dew point, wet-bulb approximation, enthalpy, and two-stream mixing.
Brayton Cycle (Gas Turbine)
PV: isentropic compress, isobaric heat in, isentropic expand, isobaric cool — jet/GT core cartoon.
Joule–Thomson Throttling
Isenthalpic expansion: ideal gas ΔT = 0; toy μ_JT inversion for real gases.
van der Waals Isotherms
Reduced (P_r,V_r,T_r) curves; critical point; subcritical wiggle vs Maxwell plateaus (qualitative).
Bénard Convection (Rayleigh)
Heated-from-below layer: Ra vs Ra_c ~1708; schematic hex/roll pattern.
Black Body: Planck Spectrum
B_λ(λ,T); Wien λ_max ∝ 1/T; Stefan–Boltzmann M = σT⁴ and numeric ∫πB_λ dλ.
Rankine Cycle (Steam)
T–s with vapor dome + schematic P–v: pump, boiler, turbine, condenser; x₄ and pressure sliders.
Refrigeration Cycle (Reverse Carnot)
PV loop like Carnot but reversed; COP_R & COP_HP; T_C/T_H in K; symbolic fridge sketch.
Vapor-Compression Refrigeration Cycle
Compressor, condenser, expansion valve, evaporator: COP, cooling capacity, pressure ratio, and p-h sketch with states 1-2-3-4.
Fin Heat Transfer
Straight rectangular fin with convection: temperature profile, mL, fin efficiency ηf, effectiveness, and heat rate vs geometry.
Lumped Capacitance Cooling
Newton cooling with Biot number, characteristic length, τ = ρVc/(hA), temperature curve, and validity check Bi < 0.1.
Pipe Friction & Moody Chart
Reynolds number, relative roughness, Swamee-Jain/Colebrook-style friction factor, and Darcy-Weisbach head loss.
Open-Channel Flow & Hydraulic Jump
Rectangular-channel Froude number, critical depth, conjugate depths, energy loss, and subcritical/supercritical regimes.
Multilayer Wall Conduction
Three layers in series: R″ = L/k, q″ and U; T(x) sketch and preset plaster/brick/wool.
Adiabatic Cloud Parcel
Lift moist air: dry Γ, LCL, toy moist lapse; RH and cartoon cloud vs height.
Engine Cycles Compared (P–V)
One canvas: Carnot, Otto, Diesel, Stirling, Rankine sketch — switch cycles, same formulas as standalone labs.
Diesel Cycle (PV)
Air-standard: adiabat compress, isobaric heat, adiabat expand, isochoric out; η(ρ_c, β).
Maxwell’s Demon (Toy)
2D billiards + gate: fast |v| crosses; ⟨|v|⟩ left/right + Landauer note.
Leidenfrost Effect (Toy)
T_plate vs ~200 °C threshold: vapor gap and lifetime curves — pedagogical, not measured boiling data.
Peltier & Seebeck (Schematic)
Current pumps heat across junction; ΔT drives toy mV — same couple, two modes.
Joule Expansion
Ideal gas into vacuum: Q = W = ΔU = 0; ΔS = nR ln 2 when volume doubles.
2D Ising Model
Square lattice Metropolis: kT/J vs |m| and E; T_c ≈ 2.27; optional field h.
Lorentz Gas (Billiard)
Point particle specularly reflected from fixed disks in a box: chaotic paths and MSD growth toward diffusion.
Site Percolation (2D)
Square lattice occupation p: clusters, left–right spanning, p_c ≈ 0.593; rough box-counting D̂ on the largest cluster.
Diffusion-Limited Aggregation (DLA)
Random walkers stick on first contact with a seed cluster on a square lattice; branched fractal growth with literature mass dimension D ≈ 1.71 in 2D and a rough box-counting D̂.
Forest Fire (Cellular Automaton)
Toroidal lattice: trees regrow with probability p, lightning ignites trees with probability f, fire spreads to four neighbors; explore intermittent bursts and SOC-like phenomenology.
Schelling Segregation Model
Two agent types on a toroidal lattice with vacancies: unhappy agents swap into random empty cells when fewer than a fraction τ of occupied Moore neighbors share their type—mild local rules, global clustering.
Kuramoto Oscillators
All-to-all coupled phases θ_i with intrinsic frequencies ω_i: order parameter r = |N⁻¹ Σ e^{iθ_i}| grows as coupling K crosses the synchronization window—classic mean-field rhythm transition.
Vicsek Model (Active Matter)
Self-propelled particles on a torus align headings with neighbors within radius R, add noise η, then drift at v₀; polarization V_a = |⟨e^{iθ}⟩| captures the flocking crossover with density ρ = N/L².
Wolfram Elementary Cellular Automata
1D binary CA with Wolfram code R∈[0,255]: space–time raster, periodic or null boundaries, single-cell or random IC, rule-bit strip, and informal class hints for textbook rules (e.g. 30, 90, 110, 184).
Eden Growth (Lattice)
Square-lattice Eden model: each step occupies a uniformly random empty von-Neumann neighbor of the cluster; compact growth with a rough interface—track perimeter P vs 2√(πN) as a roughness proxy.
Ising 2D: Wolff Cluster Updates
Ferromagnetic toroidal Ising (h = 0): Swendsen–Wang bond freezing with probability 1 − e^(−2βJ), build a same-spin cluster, flip it—fast mixing near T_c compared to single-spin Metropolis.
Hopfield Associative Memory
10×10 binary Hopfield network: Hebbian pattern storage, energy E = −½ Σ w_ij S_i S_j, and random asynchronous updates that flow downhill to fixed-point recall after noisy cues.
Bose–Einstein vs Fermi–Dirac
Grand-canonical occupation f(E) at the same T and μ: FD, BE, and classical Maxwell–Boltzmann comparison.
Ideal Gas Simulator
Bouncing particles in a box. See PV=nRT in action.
Gas Laws Interactive
Boyle's, Charles's, Gay-Lussac's laws with interactive piston.
Heat Transfer
Conduction, convection, and radiation with temperature gradients.
Phase Diagram
Temperature-pressure diagram with phase transitions.
Carnot Engine
PV diagram animation with cycle steps and efficiency.
Maxwell–Boltzmann Distribution
Histogram of |v| from Gaussian components vs the 3D Maxwell speed PDF; T and sample size.
Thermal Expansion
Linear ΔL = α L₀ ΔT; compare reference bar and heated/cooled length (schematic).
Brownian Motion
Heavy particle with random kicks and friction; trail and running ⟨r²⟩ vs time.
Otto Cycle
PV diagram: adiabatic compression/expansion and isochoric heat; η = 1 − r^{1−γ}.
Gas Mixing & Entropy
Two species separated then mixed; ΔS = 2nR ln 2 for equal volumes and moles.
Stirling Cycle
PV: two isotherms and two isochores; ideal η equals Carnot with a perfect regenerator.
Wet Steam (T–s sketch)
Vapor dome, horizontal isobar in two-phase region, quality x and superheat sketch.