The effect of main stream inlet temperature on the stability limits is illustrated in Figure 1 for the opposed reacting jet combustor over a range of equivalence ratios. Fuel lean combustion promises to be an effective means of limiting pollutant formation. Very lean combustion however adversely affects the stability of the combustion process. Thus, initial efforts are directed toward determining the lean stability limits. The primary variables which affect the stability limits of the opposed reacting jet are jet stream equivalence ratio, jet stream flow rate, and main stream inlet temperature. The main stream equivalence ratio at blowout can be reduced by increasing the jet stream equivalence ratio, however the net result is little or no reduction in the equivalence ratio of the recirculation region. Thus, extending the stability limits to lower equivalence ratios through a variation in the jet stream composition does not appear useful to gas turbine applications. Stable operation with both a lean primary and jet stream can be accomplished by increasing the jet exit velocity. An upper limit of 200 meters per second is imposed on the jet velocity in the present investigation due to a desire to avoid compressibility effects encountered at Mach numbers greater than 0.6. Compressibility effects threaten the convergence of the numerical solution and change the nature of the governing equations from elliptic to hyperbolic. In the present investigation, a jet exit velocity of 90 meters per second is selected. This minimized the number of grid points required for the numerical solution while at the same time providing a flame zone large enough to make possible good spatial resolution in the composition and temperature measurements. The most effective way of increasing the lean stability limits of the opposed reacting jet combustor is found to be an increase in primary stream inlet temperature. For a jet exit velocity of 90 meters per second and a primary stream velocity of 7 meters per second, an inlet temperature of 600 K allows stable operation to be maintained at an overall equivalence ratio as low as 0.38. An increase in jet velocity will of course reduce this stability limit further.