Heat transfer problems, solved the way your professor does them
Six calculators built on the standard Cengel correlations and resistance networks. Every solver is replayed against 100 golden cases mined from the solution manual. Results computed in your browser, no account.
Multi-Layer Wall
Series R-network: convection, up to four conduction layers, contact resistance. Q = ΔT/ΣR plus every interface temperature.
Pipe & Insulation
Cylindrical and spherical shells with inner/outer convection, including the critical radius of insulation check r_crit = k/h.
Transient Conduction
Bi check, lumped capacitance, one-term (Heisler) solution for walls, cylinders and spheres. Solve T(t) — or invert for time.
Forced Convection
Flat plate laminar/turbulent/combined, cylinder and sphere cross-flow, Dittus-Boelter tubes. Re → Nu → h → Q.
Natural Convection
Ra → Nu → h → Q for vertical plates, horizontal cylinders and plates, with optional radiation to the surroundings.
Heat Exchanger (LMTD + ε-NTU)
Counter/parallel LMTD and ε-NTU for counter, cross, and 1-2 shell-and-tube: solve duty, area, UA, or outlet temperatures.
Boiling
Nucleate-boiling flux q = h·ΔT_sat, boiling coefficient from measured flux, and Zuber critical heat flux for wires and heaters.
Condensation
Nusselt film condensation on vertical plates/tubes and horizontal tube tiers, with modified latent heat and condensate rate.
Radiation Exchange
Blackbody emission, irradiation, two-surface gray enclosure networks, and radiation shields (N+1 rule).
View Factor
Closed-form shape factors: coaxial disks, concentric spheres/cylinders, perpendicular and parallel rectangles, triangle ducts.
Verified against the corpus
The engine behind these pages is the same TypeScript engine the HeatSolve test suite replays: 100 golden cases from the Cengel & Ghajar Heat and Mass Transfer 2e solution manual (ch01–ch09), every closed-form answer recomputed before commit. When a calculator can reproduce the solution manual, it can reproduce your homework.