44 tools
Heat & Fluids
Pressure, buoyancy, pipe flow and head loss, specific and latent heat, conduction, convection, radiation and the gas laws — the two halves of thermofluids, each stating the law it comes from.
Tools in this category
- Heat & FluidsDensity CalculatorFill in any two of mass, volume and density and get the third.
- Heat & FluidsHeat Conduction CalculatorHeat flow through a solid layer by Fourier's law, with the thermal resistance and what it costs over a day and a year.
- Heat & FluidsLatent Heat CalculatorThe energy needed to melt or boil something, and how long a given heater would take to do it.
- Heat & FluidsPipe Flow Velocity CalculatorFlow velocity inside a pipe from the flow rate and the internal diameter.
- Heat & FluidsHeat Energy CalculatorEnergy needed to change the temperature of a mass, in megajoules and kilowatt-hours.
- Heat & FluidsContinuity Equation CalculatorHow fast a fluid speeds up when the pipe narrows, with the flow rate, the areas and the pressure it trades away.
- Heat & FluidsConvection Heat Transfer CalculatorHeat carried away from a surface by air or water, from Newton's law of cooling, with the area or coefficient you would need.
- Heat & FluidsFirst Law of Thermodynamics CalculatorThe change in internal energy from the heat going in and the work coming out, with the temperature change it implies.
- Heat & FluidsHydrostatic Pressure CalculatorPressure at a depth in a liquid, as gauge pressure and as absolute pressure.
- Heat & FluidsReynolds Number CalculatorReynolds number for pipe flow, the critical speed and an estimated friction factor.
- Heat & FluidsThermal Expansion CalculatorHow much a bar, rail or pipe grows when its temperature rises.
- Heat & FluidsBernoulli Equation CalculatorDownstream pressure from upstream conditions, with the velocity and height contributions shown separately.
- Heat & FluidsDarcy-Weisbach Head Loss CalculatorFriction head loss and pressure drop along a pipe, with the flow rate and the power it costs.
- Heat & FluidsCarnot Efficiency CalculatorMaximum theoretical efficiency of a heat engine between two temperatures, plus the ideal COP of a fridge and a heat pump.
- Heat & FluidsTerminal Velocity CalculatorSteady falling speed at which air resistance exactly balances weight.
- Heat & FluidsBuoyancy CalculatorUpthrust on a submerged body, the net weight in the fluid and how much of it floats below the surface.
- Heat & FluidsHydronic Water Flow Rate Calculator (Heating and Chilled Water, kW to m³/h)The water flow a heating or cooling load needs for a chosen temperature difference, and the pipe diameter or the velocity that flow gives — drawn against ΔT.
- Heat & FluidsIdeal Gas Law CalculatorAmount of substance from pressure, volume and temperature, with the molar volume.
- Heat & FluidsWater Properties Calculator (Density, Viscosity, Surface Tension vs Temperature)Density, dynamic and kinematic viscosity, surface tension and specific weight of liquid water between 0 and 100 °C — the numbers you need for a Reynolds number or a pump calculation.
- Heat & FluidsStefan-Boltzmann Radiation CalculatorHeat radiated by a hot surface, the net loss to its surroundings and the wavelength it peaks at.
- Heat & FluidsWien's Displacement Law CalculatorWavelength at which a hot body radiates most strongly, with the matching frequency and photon energy.
- Heat & FluidsPipe Friction Factor CalculatorThe Darcy friction factor from pipe diameter, wall roughness and Reynolds number, using the Swamee-Jain equation.
- Heat & FluidsAir Compressor Power Calculator (Polytropic, Multistage with Intercooling)Shaft power, the isothermal minimum, isothermal efficiency and discharge temperature of an air compressor from inlet flow, pressures, polytropic exponent, efficiency and number of stages.
- Heat & FluidsHeating Expansion Vessel Sizing CalculatorVolume of the expansion vessel for a closed heating or chilled-water circuit, from the system water volume, the fill and maximum temperatures and the pressures — with the water's expansion worked out from its density.
- Heat & FluidsMixing Temperature Calculator (Final Temperature of Two Substances)The temperature two amounts of water, or any two substances, settle at when mixed or put in contact, and the heat that moves between them.
- Heat & FluidsPipe Insulation Heat Loss CalculatorHeat lost by a hot pipe with and without insulation, the saving, the energy wasted per day and the critical insulation radius, with the cross-section drawn to scale.
- Heat & FluidsPump Operating Point Calculator (Pump Curve Meets System Curve)The flow and head a pump will really deliver in a given pipe system, from its shut-off head and one rated point and the system's static head and friction loss, with both curves drawn.
- Heat & FluidsTank Draining Time Calculator (Torricelli)How long a vertical cylindrical tank takes to empty through a hole in its bottom, the level at any moment and the flow at the start, with the tank drawn to scale.
- Heat & FluidsValve Kv and Cv Calculator (Flow Coefficient, Valve Sizing)The Kv or Cv a valve needs for a given liquid flow and pressure drop, the flow a valve of known Kv passes, and the drop it gives at your flow — with the flow-against-pressure curve.
- Heat & FluidsHazen-Williams Head Loss CalculatorHead loss, pressure drop and velocity in a water pipe from flow rate, diameter, length and the C roughness coefficient.
- Heat & FluidsFroude Number Calculator (Open Channel Flow Regime)Froude number of flow in a channel, a river or a spillway from the speed and depth, with whether the flow is subcritical or supercritical and the critical depth.
- Heat & FluidsHeat Recovery Ventilation Calculator (Supply Temperature and Energy Saved)Temperature of the fresh air leaving a heat-recovery ventilation unit, the heat it recovers and the heating still needed, and the efficiency from a measured temperature.
- Heat & FluidsIsentropic Flow Calculator (Mach Number, Static and Stagnation Properties)Static pressure, temperature, density, speed and area ratio of a compressible gas flow at a given Mach number, from its stagnation conditions.
- Heat & FluidsOtto Cycle Calculator (Petrol Engine Efficiency, Temperatures and Mean Effective Pressure)Efficiency, peak temperature and pressure, net work and mean effective pressure of the ideal air-standard Otto cycle, from compression ratio, intake state and heat added.
- Heat & FluidsStokes Settling Velocity Calculator (Sedimentation of Particles)How fast a small sphere sinks (or rises) through a fluid by Stokes' law, with its Reynolds number, whether the law applies, and the time to settle a given height.
- Heat & FluidsV-Notch Weir Calculator (Triangular Weir Flow)Flow over a sharp-crested V-notch weir from the notch angle and the head of water above its vertex, in litres per second and cubic metres per hour.
- Heat & FluidsWater Hammer Calculator (Joukowsky Pressure Surge)Pressure rise when a flow is stopped suddenly in a pipe, from the change in speed, the pressure-wave speed and the density, with the critical closing time.
- Heat & FluidsCOP, EER and kW/ton ConverterConvert coefficient of performance, energy efficiency ratio and kilowatts per ton of refrigeration.
- Heat & FluidsCooling Tower Make-Up Water Calculator (Evaporation, Blowdown, Cycles of Concentration)Water a cooling tower evaporates, bleeds off and must be topped up with, from the circulating flow, the cooling range and the cycles of concentration.
- Heat & FluidsFlue Gas Loss Calculator (Siegert Formula, Boiler Combustion Efficiency)Heat lost up the chimney as a percentage of the fuel's energy, and the combustion efficiency, from the flue gas temperature, the oxygen reading and the fuel.
- Heat & FluidsRectangular Weir Flow Calculator (Francis Formula)Flow over a sharp-crested rectangular weir from the crest length and the head of water above it, with the effect of end contractions.
- Heat & FluidsThermal Conductivity ConverterConvert W/(m·K), BTU/(h·ft·°F), BTU·in/(h·ft²·°F) and kcal/(h·m·°C).
- Heat & FluidsCooling Time Calculator (Lumped Capacitance)Temperature of a part after a given time in air or a bath, plus its thermal time constant and Biot number.
- Heat & FluidsHeat Transfer Coefficient ConverterConvert W/(m²·K), BTU/(h·ft²·°F) and kcal/(h·m²·°C).