Abstract: An aircraft gas turbine engine includes a heat exchanger module, and a core engine including an intermediate-pressure compressor, a high-pressure compressor, a high pressure turbine, and a low-pressure turbine. The high-pressure compressor is connected to the high-pressure turbine by a first shaft, and the intermediate-pressure compressor is connected to the low-pressure turbine by a second shaft. The heat exchanger module includes a central hub and heat transfer elements extending radially from the central hub and spaced in a circumferential array, for transferring heat energy from a fluid within the heat transfer elements to an inlet airflow passing over the heat transfer elements prior to entry of the airflow into an inlet to the core engine. The gas turbine engine further includes a first electric machine connected to the first shaft and positioned downstream of the heat exchanger module, and a second electric machines connected to the second shaft.

Abstract: A thermal management system for an aircraft comprises a first gas turbine engine, a first thermal bus, a first heat exchanger, and a chiller. The first thermal bus comprises a first heat transfer fluid, with the first heat transfer fluid being in fluid communication, in a closed loop flow sequence, between the first gas turbine engine, the first heat exchanger, and the chiller. Waste heat energy generated by the first gas turbine engine, is transferred to the first heat transfer fluid. The chiller is configured to lower a temperature of the first heat transfer fluid prior to the first heat transfer fluid being circulated through the gas turbine engine. The first heat exchanger is configured to transfer the waste heat energy from the first heat transfer fluid to a dissipation medium.

Abstract: A gas turbine engine for an aircraft comprises, in axial flow sequence, a compressor module, a combustor module, and a turbine module, with a first electric machine being rotationally connected to the turbine module. The first electrical machine is configured to generate a maximum electrical power PEM1 (W), and the gas turbine engine is configured to generate a maximum dry thrust T (N); and a ratio S of: S = ( Maximum ? Electrical ? Power ? Generated = P E ? M ? 1 ) ( Maximum ? Dry ? Thrust = T ) is in a range of between 2.0 and 10.0.

Abstract: A thermal management system for an aircraft includes a first gas turbine engine, first thermal bus, first heat exchanger, one or more first ancillary systems, vapour compression system, one or more second ancillary systems and second heat exchanger. A waste heat energy generated by a first gas turbine engine, and a first ancillary system, transfers to the first heat transfer fluid. A waste heat energy generated by a second ancillary system transfers to a second heat transfer fluid, and the second heat exchanger transfers the waste heat energy from the second heat transfer fluid to the first heat transfer fluid. The waste heat energy generated by a second ancillary system transfers to the first heat transfer fluid, and the first heat exchanger transfers the waste heat energy to a dissipation medium. The waste heat energy transferred to the second heat transfer fluid ranges from 20 kW to 300 kW.

Abstract: A thermal management system for an aircraft includes a first gas turbine engine, one or more first electric machines, first thermal bus and heat exchanger. The first thermal bus includes a first heat transfer fluid in a closed loop flow sequence, between the first gas turbine engine, or each first electric machine, and the first heat exchanger. Waste heat energy transfers to the first heat transfer fluid. The first heat exchanger configures to transfer waste heat energy from the first heat transfer fluid to a dissipation medium. During steady-state operation of the first gas turbine engine, the first heat transfer fluid entering the first heat exchanger has a temperature of TFLUID(° C.), and a temperature of an inlet air flow entering the first gas turbine engine has a temperature TAIR(° C.) and a ratio B is in a range of between 5.0-18.0.

Abstract: A thermal management system for an aircraft includes a first gas turbine engine, first thermal bus, first heat exchanger, one or more first ancillary systems, vapour compression system, one or more second ancillary systems and second heat exchanger. A waste heat energy generated by a first gas turbine engine, and a first ancillary system, transfers to the first heat transfer fluid. A waste heat energy generated by a second ancillary system transfers to a second heat transfer fluid, and the second heat exchanger transfers the waste heat energy from the second heat transfer fluid to the first heat transfer fluid. The waste heat energy generated by a second ancillary system transfers to the first heat transfer fluid, and the first heat exchanger transfers the waste heat energy to a dissipation medium. The waste heat energy transferred to the second heat transfer fluid ranges from 20 kW to 300 kW.

Abstract: A thermal management system for an aircraft includes a first gas turbine engine, one or more first electric machines rotatably coupled to the first gas turbine engine, a first thermal bus, and a first heat exchanger. Waste heat energy generated by at least one first gas turbine engine, and first electric machine, transfers to the first heat transfer fluid. The first heat exchanger directs a first proportion of the first heat transfer fluid through a first heat dissipation portion wherein a first proportion of the waste heat energy transfers to a first dissipation medium dependent on the first dissipation medium temperature and mass flow rate. The first heat exchanger directs a second proportion of the first heat transfer fluid through a second heat dissipation portion wherein the second proportion of waste heat energy transfers to a second dissipation medium dependent on the second dissipation medium temperature and mass flow rate.

Abstract: A thermal management system for an aircraft comprises a first gas turbine engine, a first thermal bus, a first heat exchanger, and a chiller. The first thermal bus comprises a first heat transfer fluid, with the first heat transfer fluid being in fluid communication, in a closed loop flow sequence, between the first gas turbine engine, the first heat exchanger, and the chiller. Waste heat energy generated by the first gas turbine engine, is transferred to the first heat transfer fluid. The chiller is configured to lower a temperature of the first heat transfer fluid prior to the first heat transfer fluid being circulated through the gas turbine engine. The first heat is exchanger is configured to transfer the waste heat energy from the first heat transfer fluid to a dissipation medium.

Abstract: A thermal management system for an aircraft includes a first gas turbine engine, one or more first electric machines, a first thermal bus, and a first heat exchanger. The first thermal bus includes a first heat transfer fluid in a closed loop flow sequence, between the first gas turbine engine, the or each first electric machine, and the first heat exchanger. Waste heat energy generated by at least one of the first gas turbine engine, and the or each first electric machine, is transferred to first heat transfer fluid. When airspeed of aircraft is less than Mn0.6, the first heat exchanger transfers the waste heat energy from the first heat transfer fluid to a first dissipation medium. When the airspeed of the aircraft is greater than Mn0.6, the first heat exchanger is configured to transfer the waste heat energy from the first heat transfer fluid to a second dissipation medium.

Abstract: A thermal management system for an aircraft includes a first thermal bus including one or more first heat sources, a heat sink, a vapour compression system, and one or more second heat sources. The vapour compression system includes a compressor, a condenser, a receiver, a first side of a recuperator, an expansion valve, an evaporator, a second side of the recuperator, and the compressor. A first heat flow (Q1) of waste heat energy generated by the first heat sources is transferred via the first heat transfer fluid to the heat sink. A second heat flow (Q2) of waste heat energy generated by the second heat source(s) being transferred via the evaporator to a refrigerant. A third heat flow (Q3) of heat energy in the refrigerant is transferred via the condenser to the first heat transfer fluid. The controller is configured to ensure that: 1.1*Q2<Q3<3.0*Q2.

Abstract: A thermal management system for an aircraft comprises a first gas turbine engine, one or more first electric machines rotatably coupled to the first gas turbine engine, a first thermal bus, a first heat exchanger, and one or more first ancillary systems. The first thermal bus comprises a first heat transfer fluid, with the first heat transfer fluid being in fluid communication, in a closed loop flow sequence, between the or each first electric machine, the first gas turbine engine, the first heat exchanger, and the or each first ancillary system. Waste heat energy generated by at least one of the first gas turbine engine, the or each first electric machine, and the or each first ancillary system, is transferred to the first heat transfer fluid. The first heat exchanger is configured to transfer the waste heat energy from the first heat transfer fluid to a dissipation medium.

Abstract: A composition of crystalline TGF-.beta.2 is described. The tertiary structure of the protein homodimer determined by X-ray crystallography to 2.1 angstrom resolution is shown. This structure provides data useful in the rational design of drugs to mimic the physiologic properties of proteins of the TGF-.beta. family.

Abstract: In known guidance systems, the missile is guided by a control loop which includes the missile and a ground-based tracker, the tracker determining the relative positions of the missile and target and hence the lateral acceleration to be applied to the missile. However, these systems do not take account of the lateral acceleration generated by the coupling of the missile acceleration along its longitudinal axis and the angle between the body of the missile and the sightline, as in cases where acceleration is small the effect is insignificant. Described herein is a system for modifying the demand component to effect compensation for the lateral acceleration component imparted to the missile by virtue of its angle of incidence. This is accomplished by modifying the demand component in accordance with a stored predetermined time-varying gain term thereby to effect compensation of the lateral acceleration component imparted to the missile by virtue of the angle of incidence of the missile.

Abstract: To prevent dissolution of sand grains or of the original bond between these grains around a well when hot aqueous fluid is passed through the well in an oil recovery process, the sand grains are at least once treated with a solution of Al ions in a solvent such as water. Such treatment with Al ions of sand grains is also beneficial when the grains have been consolidated by means of a silicon polyhalide. Attack of the bond between the grains by formation water is then considerably decreased.

Abstract: Sand grains coated with a solid non-cured epoxy resin with a softening point above 35.degree. C. are placed in a well for gravel pack, well repair or fracturing purposes. The epoxy resin softens at formation temperature and reacts with a hardener (such as a tertiary amine) diluted in water present in the pore space of the mass of sand grains. A consolidated mass of sand grains is thus obtained. The coated sand grains can be transported to the well site and stored over long periods at relatively high temperatures without risk of quality decrease.

Abstract: A reservoir encountered by a drilling fluid-containing borehole can be sampled and/or a liquid can be removed from within a borehole by arranging conduits and a packer for isolating the reservoir or a selected fluid-removal location and then gas-lifting liquid by injecting an aqueous liquid solution which generates nitrogen gas within the borehole, with the depth of the injection and the rates of fluid inflow and outflow being adjusted to maintain a selected drawdown at the depth of the fluid-removal location.