A gas turbine engine (400; 500; 600) comprising: a compressor section; a combustor section; a turbine section; and a nozzle section, wherein the compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section; a cooling duct (407; 507; 638) is defined separate from the core flow path; a waste heat recovery system (402; 502; 602) is configured within the gas turbine engine, the waste heat recovery system comprising: a heat rejection heat exchanger (428; 528; 628) arranged within the cooling duct; whereby the waste heat recovery system (402; 502; 602) further comprises: a blower (436; 536; 636) arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger; a recuperating heat exchanger (426; 526; 626) being a working fluid-to-working fluid heat exchanger; a heat recovery heat exchanger (432; 532; 632) being a working fluid-to-exhaust heat exchanger; and a working fluid configured to flow through each of the heat recovery heat exchanger (432; 532; 632), the recuperating heat exchanger (426; 526; 626), and the heat rejection heat exchanger (428; 528; 628); wherein the heat rejection heat exchanger is thermally connected to a portion of the cooling duct (407; 507; 638), the heat rejection heat exchanger being a working fluid-to-air heat exchanger. a compressor section; a combustor section; a turbine section; and a nozzle section, wherein the compressor section, the combustor section, the turbine section, and the nozzle section define a core flow path that expels through the nozzle section; a cooling duct (407; 507; 638) is defined separate from the core flow path; a waste heat recovery system (402; 502; 602) is configured within the gas turbine engine, the waste heat recovery system comprising: a heat rejection heat exchanger (428; 528; 628) arranged within the cooling duct; whereby the waste heat recovery system (402; 502; 602) further comprises: a blower (436; 536; 636) arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger; a recuperating heat exchanger (426; 526; 626) being a working fluid-to-working fluid heat exchanger; a heat recovery heat exchanger (432; 532; 632) being a working fluid-to-exhaust heat exchanger; and a working fluid configured to flow through each of the heat recovery heat exchanger (432; 532; 632), the recuperating heat exchanger (426; 526; 626), and the heat rejection heat exchanger (428; 528; 628); wherein the heat rejection heat exchanger is thermally connected to a portion of the cooling duct (407; 507; 638), the heat rejection heat exchanger being a working fluid-to-air heat exchanger. a heat rejection heat exchanger (428; 528; 628) arranged within the cooling duct; whereby the waste heat recovery system (402; 502; 602) further comprises: a blower (436; 536; 636) arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger; a recuperating heat exchanger (426; 526; 626) being a working fluid-to-working fluid heat exchanger; a heat recovery heat exchanger (432; 532; 632) being a working fluid-to-exhaust heat exchanger; and a working fluid configured to flow through each of the heat recovery heat exchanger (432; 532; 632), the recuperating heat exchanger (426; 526; 626), and the heat rejection heat exchanger (428; 528; 628); wherein the heat rejection heat exchanger is thermally connected to a portion of the cooling duct (407; 507; 638), the heat rejection heat exchanger being a working fluid-to-air heat exchanger. a blower (436; 536; 636) arranged within the cooling duct and configured to generate a pressure drop across the heat rejection heat exchanger; a recuperating heat exchanger (426; 526; 626) being a working fluid-to-working fluid heat exchanger; a heat recovery heat exchanger (432; 532; 632) being a working fluid-to-exhaust heat exchanger; and a working fluid configured to flow through each of the heat recovery heat exchanger (432; 532; 632), the recuperating heat exchanger (426; 526; 626), and the heat rejection heat exchanger (428; 528; 628); wherein the heat rejection heat exchanger is thermally connected to a portion of the cooling duct (407; 507; 638), the heat rejection heat exchanger being a working fluid-to-air heat exchanger.