| This work is part of a large-scale project directed towards developing a new internal combustion engine with a high thermal efficiency and clean-burn of intake mixtures consisting of direct-injected diesel fuel and air mixtures. The new engine uses a gas-porous, reticulated ceramic matrix to add heat (energy) to the reactants immediately prior to combustion, and also has the matrix hot enough to ignite the reactants on its surface. A 20 pores-per-inch (7.87 pores-per-centimeter) matrix made of Zirconia Toughened Alumina was used for the testing. Numerical simulations of the cycle suggest thermal efficiencies as high as 40% possible. Specifically, this work was to build the new engine and to capture the engine's cycle on pressure versus crank angle plots to determine the effects of engine loading, intake mass flow rate of reactants, and intake timing on engine speed, cylinder pressure, and output torque. The cylinder pressure of a cycle is decomposed into the pressure due to air injection and to the pressure due to combustion. Results have shown that running the engine with air injection beginning late in the cycle, at approximately 20{dollar}spcirc{dollar} After-Top-Dead-Center (ATDC), and with fuel injection ending early in the cycle, by 45{dollar}spcirc{dollar} ATDC, was able to produce the highest levels of output torque (proportional to work/cycle) and cylinder pressure. In conclusion, the new engine has shown the potential to become a clean-burning, thermally efficient engine. Further modifications of the fuel delivery system are needed to make full use of the engine's capabilities of ceramic surface ignition. |
