Gas turbine combustion system with rich premixed fuel reforming and methods of use thereof

A gas turbine engine system (10) includes a compressor (12), a combustor (14), and a turbine (16); a fuel system (20) comprising one or more fuel circuits (102) configured to provide fuel from a fuel flow to the combustor; a non-catalytic fuel reformer (32, 100) in fluid communication with the one or more fuel circuits, wherein the non-catalytic fuel reformer is configured to receive an oxidant from an oxidant flow and a fraction of fuel in the one or more fuel circuits in a predetermined ratio and reform the fraction of the fuel to produce a reformate; and a control system (18) configured to regulate at least one of fuel flow and oxidant flow to the non-catalytic fuel reformer to control a Modified Wobbe Index of the fuel entering the combustor..