Advanced Combustion Calculators

Chemical Equation Balancer for Combustion

Balance the complete combustion equation for a hydrocarbon fuel CxHy, finding the oxygen, CO2, and H2O coefficients.

Combustion Chamber Pressure Calculator

Calculate the pressure change inside a fixed-volume combustion chamber from changes in gas moles and temperature.

Combustion Chamber Temperature Calculator

Calculate the resulting gas temperature inside a combustion chamber after a known quantity of heat is added.

Combustion Chamber Volume Calculator

Calculate the internal volume of a cylindrical combustion chamber from its diameter and length.

Combustion Efficiency Loss Calculator

Calculate overall combustion efficiency by summing stack loss, unburned fuel loss, and radiation loss components.

Combustion Reaction Products Calculator

Calculate the full molar breakdown of CO2, H2O, excess O2, and N2 produced from combusting a hydrocarbon fuel with excess air.

Combustion Residence Time Calculator

Calculate how long combustion gases spend traveling through a combustion chamber from chamber length and gas velocity.

Dew Point of Flue Gas Calculator

Calculate the water vapor dew point temperature of flue gas from its moisture content, to prevent corrosive condensation.

Dry Basis to Wet Basis Calculator

Convert a dry-basis flue gas concentration back to its actual wet-basis value including water vapor dilution.

Equivalence Ratio Calculator

Calculate the equivalence ratio (phi) of a combustion mixture from actual and stoichiometric air-fuel ratios.

Fuel Blend Calculator

Calculate the mass-weighted average heating value of a two-component fuel blend from mass fractions and individual heating values.

Heat Transfer from Combustion Calculator

Calculate the convective heat transfer rate from hot combustion gas to a cooler surface using the standard convection model.

Lambda Calculator (Combustion)

Calculate the lambda value of a combustion mixture from actual and stoichiometric air-fuel ratios.

Moisture Correction Calculator

Calculate the as-received heating value of a fuel after correcting for moisture content and latent heat losses.

Oxidizer Requirement Calculator

Calculate the total oxidizer required for combustion when using enriched air or pure oxygen instead of standard air.

Stack Loss Calculator

Calculate stack loss percentage from stack temperature, ambient temperature, and CO2 percentage using the Siegert relation.

Stoichiometric Combustion Calculator

Calculate the stoichiometric oxygen and air requirement, on a molar basis, to completely combust a hydrocarbon fuel CxHy.

Wet Basis to Dry Basis Gas Calculator

Convert a wet-basis flue gas concentration to its dry-basis equivalent by removing water vapor dilution.

Deeper Combustion Chemistry and Thermodynamics

Beyond the basic air-fuel and heat calculations, combustion engineering involves more specialized analysis — equivalence ratio and lambda expressing how far a mixture sits from stoichiometric, moisture and basis corrections for gas composition, and combustion chamber conditions that determine reaction completeness. Eighteen calculators here cover this more advanced combustion chemistry and thermodynamics.

Popular Advanced Combustion Calculators

Highlights across mixture ratios, gas basis conversion, and chamber conditions:

  • Equivalence Ratio Calculator — calculates the ratio of actual to stoichiometric fuel-air ratio, showing whether a mixture runs rich or lean.
  • Lambda (λ) Calculator — calculates the inverse of equivalence ratio, the standard lambda notation used in automotive and industrial combustion control.
  • Stoichiometric Combustion Calculator — balances a complete combustion reaction to find exact reactant and product quantities.
  • Stack Loss Calculator — estimates the percentage of fuel energy lost as sensible heat in flue gas leaving the stack.
  • Dew Point of Flue Gas Calculator — calculates the temperature at which flue gas moisture (and acidic condensate) begins to condense.

Why Lambda and Equivalence Ratio Are Just Inverses of Each Other

Equivalence ratio (φ) compares actual fuel-air ratio to the stoichiometric ratio directly, so φ greater than 1 means a rich, fuel-heavy mixture, while lambda (λ) is defined as the reciprocal of φ, so lambda greater than 1 means a lean, excess-air mixture — the same physical mixture, described in two conventions that different industries have standardized on. Automotive engine control almost universally uses lambda, while industrial burner and furnace combustion often uses equivalence ratio or excess air percentage, which is exactly why converting between them correctly matters when combustion concepts cross between those two worlds.

Frequently Asked Questions

Why does flue gas dew point matter for stack design?
Flue gas moisture (and any sulfur trioxide present) condenses into corrosive liquid once gas temperature drops below its dew point, so stacks and heat recovery equipment are designed to either stay above that dew point or use corrosion-resistant materials if operating below it.

Explore More

Need the basic stoichiometry these build on? See the Air & Fuel Calculators, or check flame-level physics in the Flame Calculators.