Thermodynamics & Fluids
Energy, heat engines, refrigeration, fluid statics and dynamics, and heat transfer.
105 topics: 36 beginner, 35 intermediate, 34 advanced.
About this discipline
Thermodynamics explains how energy is converted between heat and work, and why every engine, refrigerator and power plant is limited in its efficiency. Fluid mechanics explains how liquids and gases flow, which determines pumps, pipes, turbines and aircraft.
The course starts with systems, properties and the first and second laws, then moves to power cycles and refrigeration, then to fluid statics and flow in pipes, and finally to heat transfer, compressible flow and computational fluid dynamics.
Who it is for
Mechanical, chemical and energy engineering students, HVAC and refrigeration technicians, and engineers in power generation, process plants and building services.
How the levels build
Beginner topics cover systems, temperature, pressure, the first law and ideal gases. Intermediate topics cover cycles, steam tables, pumps, pipe flow and drag. Advanced topics cover compressible flow, CFD, conduction, convection, radiation and heat exchangers.
Use cases
- Sizing a heat exchanger for a process stream.
- Estimating the pump power needed for a water main.
- Comparing the efficiency of a gas turbine and a steam plant.
- Designing the cooling of an electronics enclosure with heat sinks and fans.
Beginner Thermodynamics & Fluids
Topic 1System and surroundingsA thermodynamic system is the region studied; everything else is surroundings.Topic 2Open, closed and isolated systemsClassified by whether mass and energy can cross the boundary.Topic 3Properties and statePressure, temperature, volume and others define the state of a substance.Topic 4Temperature and zeroth lawBodies in thermal equilibrium with a third are in equilibrium with each other.Topic 5Temperature scalesCelsius, Fahrenheit and Kelvin; absolute zero is 0 K.Topic 6PressureForce per unit area; absolute pressure equals gauge plus atmospheric.Topic 7Specific heatEnergy needed to raise one kilogram by one kelvin.Topic 8Heat and workTwo ways energy crosses a boundary; neither is a property of the system.Topic 9Internal energy and enthalpyU is microscopic energy; H=U+PV is convenient for flow processes.Topic 10First law of thermodynamicsEnergy is conserved: ΔU=Q-W.Topic 11Ideal gas lawPV=nRT approximates gases at low pressure and high temperature.Topic 12Thermodynamic processesIsothermal, isobaric, isochoric and adiabatic describe constant property paths.Topic 13P-V diagramsArea under a curve represents work done by or on the system.Topic 14Phase changeHeating a substance at constant pressure absorbs latent heat during melting or boiling.Topic 15Property tables and steam tablesProvide v, u, h and s for water at given states.Topic 16Quality of a mixtureFraction of vapour mass in a saturated liquid-vapour mixture.Topic 17Compressibility factorCorrects ideal gas behaviour for real gases.Topic 18Energy balance for control volumesIncludes flow work and enthalpy of streams crossing boundaries.Topic 19Steady-flow devicesTurbines, compressors, nozzles, diffusers and heat exchangers analysed with the first law.Topic 20ThrottlingPressure drop at constant enthalpy; basis of refrigeration expansion valves.Topic 21Second law of thermodynamicsHeat cannot spontaneously flow from cold to hot; processes have direction.Topic 22Heat enginesConvert heat into work operating between hot and cold reservoirs.Topic 23Refrigerators and heat pumpsUse work to move heat from cold to hot; performance measured by COP.Topic 24Carnot cycleThe ideal reversible engine with efficiency 1-Tc/Th.Topic 25EntropyA measure of disorder and irreversibility; entropy of an isolated system never decreases.Topic 26T-s diagramsVisualise cycles and heat transfer as area on a temperature-entropy plot.Topic 27Isentropic efficiencyCompares real turbine or compressor work with the ideal reversible one.Topic 28ExergyThe maximum useful work available from a system relative to the environment.Topic 29Irreversibility and lost workFriction and heat transfer across a finite temperature difference destroy exergy.Topic 30Otto cycleIdeal cycle for spark-ignition engines; efficiency depends on compression ratio.Topic 31Diesel cycleIdeal compression-ignition cycle with heat added at constant pressure.Topic 32Brayton cycleGas turbine cycle with compression, combustion and expansion.Topic 33Rankine cycleBasic steam power plant cycle with boiler, turbine, condenser and pump.Topic 34Reheat and regenerationImprove Rankine efficiency by raising mean heat addition temperature.Topic 35Combined cycle plantsGas turbine exhaust heats a steam cycle to reach over 55% efficiency.Topic 36Vapour compression refrigerationCompressor, condenser, expansion valve and evaporator cycle.
Intermediate Thermodynamics & Fluids
Topic 37RefrigerantsWorking fluids chosen for thermodynamic properties and environmental impact.Topic 38Air conditioning and psychrometricsCharts of humid air describe humidity, enthalpy and cooling loads.Topic 39CombustionFuel oxidises releasing energy; stoichiometry gives air-fuel ratios.Topic 40Adiabatic flame temperatureThe temperature reached by combustion without heat loss.Topic 41Internal combustion engine performanceIndicated and brake power, mean effective pressure and efficiency.Topic 42Gas mixturesDalton's law of partial pressures and mixture properties.Topic 43Chemical equilibriumA mixture reaches a state where forward and reverse reaction rates match.Topic 44Thermodynamic relationsMaxwell relations and property derivatives link measurable quantities.Topic 45Fluid propertiesDensity, viscosity, surface tension and compressibility characterise fluids.Topic 46ViscosityResistance to shear; Newtonian fluids have shear stress proportional to velocity gradient.Topic 47Fluid staticsPressure increases with depth as P=ρgh.Topic 48Manometers and pressure measurementUse fluid column heights to measure pressure differences.Topic 49BuoyancyUpthrust equals the weight of fluid displaced.Topic 50Forces on submerged surfacesHydrostatic force acts at the centre of pressure below the centroid.Topic 51Fluid kinematicsDescribes streamlines, pathlines, and velocity fields.Topic 52Continuity equationMass is conserved: A1V1=A2V2 for incompressible flow.Topic 53Bernoulli equationAlong a streamline pressure, kinetic and potential energy per unit volume sum to a constant.Topic 54Pitot tubes and Venturi metersMeasure velocity and flow rate using pressure differences.Topic 55Momentum equationNet force on a control volume equals rate of change of momentum flux.Topic 56Laminar and turbulent flowSmooth layers versus chaotic mixing; predicted by Reynolds number.Topic 57Reynolds numberRe=ρVD/μ compares inertial to viscous forces.Topic 58Pipe flowPressure drop depends on velocity, diameter, length and roughness.Topic 59Darcy-Weisbach equationhf=f(L/D)V²/2g gives head loss from friction.Topic 60Moody chartGives friction factor as a function of Reynolds number and relative roughness.Topic 61Minor lossesValves, bends and fittings add loss coefficients.Topic 62Pipe networksHardy Cross and computational methods solve flows in loops.Topic 63PumpsAdd energy to fluids; operating point is where pump curve meets system curve.Topic 64Pump affinity lawsFlow, head and power vary with speed and impeller diameter.Topic 65Cavitation and NPSHLocal pressure below vapour pressure causes bubbles that damage pumps.Topic 66TurbinesPelton, Francis and Kaplan turbines extract energy from water.Topic 67Fans and compressorsRaise gas pressure; axial and centrifugal types.Topic 68Dimensional analysis in fluidsBuckingham Pi theorem derives dimensionless groups.Topic 69Similitude and model testingScale models match Reynolds, Froude or Mach numbers.Topic 70Boundary layerA thin region near a surface where viscosity matters.Topic 71Drag and liftForces on bodies in flow; drag coefficient and lift coefficient quantify them.
Advanced Thermodynamics & Fluids
Topic 72Flow separationBoundary layer detaches under adverse pressure gradient causing stall and wake.Topic 73Airfoil aerodynamicsShape generates lift through pressure difference and circulation.Topic 74Open channel flowFlow with free surface, described by Manning's equation.Topic 75Hydraulic jumpAn abrupt rise in water level when flow changes from supercritical to subcritical.Topic 76Compressible flowDensity changes matter when Mach number exceeds about 0.3.Topic 77Mach number and speed of soundMa=V/c; sound speed in air is about 343 m/s.Topic 78Isentropic nozzle flowConverging-diverging nozzles accelerate gas to supersonic speed.Topic 79Normal shock wavesAbrupt supersonic-to-subsonic transitions with entropy rise.Topic 80Navier-Stokes equationsFundamental equations governing viscous fluid motion.Topic 81Potential flowIdealised inviscid, irrotational flow modelled with stream functions.Topic 82Turbulence modellingk-epsilon and LES approximate unresolved turbulent fluctuations.Topic 83Computational fluid dynamicsNumerically solves flow equations on a mesh.Topic 84ConductionHeat flows through solids by Fourier's law q=-k dT/dx.Topic 85Thermal resistanceAnalogous to electrical resistance; R=L/kA for a wall.Topic 86ConvectionHeat transfer by fluid motion, q=hA(Ts-T∞).Topic 87Natural and forced convectionDriven by buoyancy or external flow respectively.Topic 88Nusselt numberDimensionless convective heat transfer coefficient.Topic 89RadiationEnergy emitted by all bodies; Stefan-Boltzmann law q=εσT⁴.Topic 90View factorsFraction of radiation leaving one surface that strikes another.Topic 91FinsExtended surfaces increase heat transfer area.Topic 92Transient conductionLumped capacitance and Heisler charts model temperature change over time.Topic 93Heat exchangersTransfer heat between fluids; parallel and counterflow arrangements.Topic 94LMTD and NTU methodsDesign and rating methods for heat exchangers.Topic 95Boiling and condensationHigh heat transfer rates through phase change.Topic 96Heat pipesPassive devices transferring heat via evaporation and condensation.Topic 97Electronics coolingHeat sinks, fans and liquid cooling keep chips within limits.Topic 98Building thermal analysisHeating and cooling loads from conduction, solar gain and ventilation.Topic 99Mass transfer basicsDiffusion and convection of species, governed by Fick's law.Topic 100CryogenicsEngineering at very low temperatures for liquefied gases and superconductors.Topic 101Fuel cellsConvert chemical energy directly to electricity with high efficiency.Topic 102Geothermal and solar thermal systemsRenewable heat sources for power and heating.Topic 103Energy efficiency and sustainabilityEvaluate systems on life-cycle energy and emissions.Topic 104Large eddy simulationResolves large turbulent eddies and models only the small ones.Topic 105Organic Rankine cycleUses organic fluids to generate power from low-temperature heat sources.
Frequently asked questions
What is Thermodynamics & Fluids?
Energy, heat engines, refrigeration, fluid statics and dynamics, and heat transfer.
How many topics are in Thermodynamics & Fluids?
105 topics, ordered from beginner to advanced: 36 beginner, 35 intermediate and 34 advanced.
Where should a beginner start in Thermodynamics & Fluids?
Start with "System and surroundings" and work through the list in order. Each topic builds on the one before it.
Why can no engine be 100 percent efficient?
The second law requires some heat to be rejected to a cold reservoir, so the efficiency of any heat engine is always below one.
What is the difference between pressure and head?
Head is pressure divided by density times gravity, so it expresses the energy per unit weight of fluid as a height. It is convenient for pumps and head losses.
When is a fluid treated as incompressible?
When the speed is well below Mach 0.3 and density changes are small. Liquids are usually incompressible, and gases at low speed can be treated the same way.
Why does a pipe get harder to push water through when the flow doubles?
Friction loss grows roughly with the square of velocity, so doubling the flow can raise the pressure loss about four times.
Do I need CFD for every fluid problem?
No. Use simple correlations and hand calculations first. CFD is valuable when geometry is complex or when detail is needed, and it still needs checking against data.
Practise in the interactive course with quizzes, tests and labs.