A premixing device is provided. The premixing device includes an air inlet configured to introduce compressed air into a mixing chamber of the premixing device and a fuel plenum configured to provide a fuel to the mixing chamber via a circumferential slot and over a pre-determined profile adjacent the fuel plenum, wherein the pre-determined profile facilitates attachment of the fuel to the profile to form a fuel boundary layer and to entrain incoming air through the fuel boundary layer to facilitate mixing of fuel and air in the mixing chamber.