A combustion device used in gas turbine engines to produce propulsion or rotate a shaft for power generation includes a can-annular combustor with a system of fuel and air inlet passages and nozzles that results in an optimal combustion environment of premixed fuel and air. The fuel-air inlets are placed at various longitudinal locations and circumferentially distributed, and direct the flow tangentially or nearly tangent to the can liner. The combustion device provides effective mixing of fuel and air, creates an environment for combustion that reduces pollutant emissions, reduces the need for costly pollution control devices, enhances ignition and flame stability, reduces piloting issues, and improves vibration reduction.