A turbofan gas turbine engine includes, in axial flow sequence, a heat exchanger module, a fan assembly, a compressor module, and a turbine module. The fan assembly includes fan blades defining a corresponding fan area (A.sub.FAN). The heat exchanger module is in fluid communication with the fan assembly by an inlet duct, and includes radially-extending vanes arranged in a circumferential array with at least one vane including a heat transfer element for heat transfer from a first fluid contained within each element to an airflow passing over a surface of each heat transfer element before entering the fan assembly inlet. Each heat transfer element extends axially along the corresponding vane, with a swept heat transfer element area (A.sub.HTE) being the wetted surface area of all heat transfer elements in contact with the airflow. A Fan to Element Area parameter F.sub.EA of A.sub.HTE/A.sub.FAN lies in the range of 47 to 132.

An apparatus and method of forming a hybrid heat exchanger including a first manifold defining a first fluid inlet and a second manifold defining a second fluid inlet. A monolithic core body includes a first set of flow passages in fluid communication with the first manifold and a second set of flow passages is in communication with the second manifold. At least a portion of the first manifold or the second manifold has a tunable coefficient of thermal expansion that is less than a coefficient of thermal expansion of the structurally rigid monolithic core.

An apparatus and method of forming a hybrid heat exchanger including a first manifold defining a first fluid inlet and a second manifold defining a second fluid inlet. A monolithic core body includes a first set of flow passages in fluid communication with the first manifold and a second set of flow passages is in communication with the second manifold. At least a portion of the first manifold or the second manifold has a tunable coefficient of thermal expansion that is less than a coefficient of thermal expansion of the structurally rigid monolithic core.

An Ericsson cycle turbine engine. The Ericsson cycle turbine may comprise: a centrifugal gas compressor, shaft, at least one heat exchanger, and a reaction turbine. The centrifugal gas compressor may function as a spinning wheel trompe and may be fed with a gas-liquid mixture. The centrifugal gas compressor may separate a gas from the gas-liquid mixture and compress that gas via centrifugal acceleration. The shaft may couple to the downstream end of the centrifugal gas compressor and may have an annular space to permit the compressed gas to travel therein. The heat exchanger may introduce heat to the compressed gas, such that isothermal expansion is approached. The reaction turbine may couple to the downstream end of the shaft and may rotate the shaft when releasing the compressed gas against a plurality of vanes. The liquid may be mercury, oil, or water. The gas may be helium, air, argon, or ammonia.

An Ericsson cycle turbine engine. The Ericsson cycle turbine may comprise: a centrifugal gas compressor, shaft, at least one heat exchanger, and a reaction turbine. The centrifugal gas compressor may function as a spinning wheel trompe and may be fed with a gas-liquid mixture. The centrifugal gas compressor may separate a gas from the gas-liquid mixture and compress that gas via centrifugal acceleration. The shaft may couple to the downstream end of the centrifugal gas compressor and may have an annular space to permit the compressed gas to travel therein. The heat exchanger may introduce heat to the compressed gas, such that isothermal expansion is approached. The reaction turbine may couple to the downstream end of the shaft and may rotate the shaft when releasing the compressed gas against a plurality of vanes. The liquid may be mercury, oil, or water. The gas may be helium, air, argon, or ammonia.

The heat exchanger is generally ring-shaped and includes a plurality of heat exchange modules (2), which are mutually independent, being distributed about the axis (A1) of the ring. The modules (2) are assembled with one another, being successively spaced apart in pairs, a space (E1) being created between two adjacent modules (2). At least one of the spaces (E1) receives at least one conductive heat-transfer element (7) extending between respective walls of at least two adjacent the modules (2) which are oriented facing one another.

An engine assembly includes a combustor, a fuel cell stack integrated with the combustor, and a pre-burner system fluidly connected to the fuel cell stack. The fuel cell stack is configured to direct fuel and air exhaust from the fuel cell stack into the combustor. The pre-burner system is configured to control a temperature of an air flow directed into the fuel cell stack. The combustor is configured to combust the fuel and air exhaust from the fuel cell stack into one or more gaseous combustion products that drive a downstream turbine. The engine assembly can further include a catalytic partial oxidation convertor that is fluidly connected to the fuel cell stack. The catalytic partial oxidation convertor is configured to develop a hydrogen rich fuel stream to be directed into the fuel cell stack.

The present disclosure provides systems and methods wherein power production can be achieved with combustion of a fuel utilizing flameless combustion. A fuel may be combusted in a combustor/turbine in a substantially flameless operation to produce a combustion product stream that can be expanded for power generation. After expansion, the output stream can be treated to generate a recycle CO.sub.2 stream into which an oxidant can be input. The recycle CO.sub.2 stream including the oxidant can be injected into the combustor/turbine to effect combustion in a substantially flameless state. Various control schemes can be implemented to automatically control the concentration of oxygen present in the recycle CO.sub.2 stream that is injected into the combustor/turbine in order to achieve and/or maintain substantially flameless combustion.

The present disclosure provides systems and methods wherein power production can be achieved with combustion of a fuel utilizing flameless combustion. A fuel may be combusted in a combustor/turbine in a substantially flameless operation to produce a combustion product stream that can be expanded for power generation. After expansion, the output stream can be treated to generate a recycle CO.sub.2 stream into which an oxidant can be input. The recycle CO.sub.2 stream including the oxidant can be injected into the combustor/turbine to effect combustion in a substantially flameless state. Various control schemes can be implemented to automatically control the concentration of oxygen present in the recycle CO.sub.2 stream that is injected into the combustor/turbine in order to achieve and/or maintain substantially flameless combustion.

Systems and methods for gas turbine or jet engines may include, among other things, one or more electric heating elements located within a combustion chamber of a gas turbine engine, a combustion chamber of a jet engine, or an afterburner of a jet engine. A combustion chamber and/or an afterburner may be configured to generate heated gas by using the one or more electric heating elements to heat gases within the combustion chamber and/or afterburner. A combustion chamber and/or an afterburner may be configured to generate an exhaust output based on the heated gas. The exhaust output may drive a turbine which generates electricity or mechanical energy. Thrust from the exhaust output from a jet engine may propel a vehicle.