ME 569

HW #1

Due 9-16-96

1) Consider a F=0.8 mixture of decane (C₁₀H₂₂) and air at 298K and 1 atm.

a) What is the mass fraction of air in the initial mixture?

b) What is the mole fraction of fuel in the initial mixture?

c) What is the mole fraction of CO₂ in theproducts on a dry basis?

d) What is the absolute enthalpy of the reactants in [kJ/kmol-fuel]?

e) Assuming ideal products compute the constant pressure adiabatic flame temperature in [K] and compare to the value you obtain from the program HPFLAME which came with the book. Do not assume that the products have a constant specific heat.

2) One mole of H₂ and one mole of O₂ are placed in a box and allowed to reach equilibrium to produce H₂O.

a) Plot the mole fraction of all of the species as a function of temperature (2000-3000 K) for a pressure of 1 atm.

b) Plot the mole fraction of all of the species as a function of pressure(0.01 - 1 atm) for a temperature of 3000 K.

3) For a decane-air mixture create the following graphs of adiabatic flame temperature (with constant volume) versus equivalence ratio:

a) For mixtures with 0.5 ² F ² 1.0, compute T_ad assuming ideal products

b) For mixtures with 1.0 ² F ² 2.0, compute T_ad using the water-gas equilibrium

c) For all mixtures compute T_ad for full equilibrium products