Heat Transfer to Air-Ethanol and Air-Methanol Sprays Flowing in Heated Ducts and Across Heated Intake Valves

Heat-transfer data are reported for stoichiometric air/ethanol and air/methanol sprays flowing through a heated intake port and across a heated intake valve. Air flowrates varying from 0.45-10 g/s were used with fuel flowrates set at the appropriate stoichiometric values. Intake port temperatures were held at values ranging from 30-120°C and inlet valve temperatures at values from 50-300°C. At temperatures up to approximately 80°C surfaces were wetted with fuel and heat transfer was mainly convective. Above 80°C nucleate boiling set in and dry patches began to form. Above 230°C film boiling occurred and heat transfer became very unstable.