An evaporative cooling pack formed from first and second corrugated media sheets is provided. The evaporative cooling pack cools a flow of air using a cooling fluid. The first and second corrugated media sheets have flutes that extend at different angles relative to a reference line and at such relative angles and have flute pitches that inhibit nesting of the adjacent sheets.

A turbomachine engine can include a fan assembly, a pitch change mechanism, a vane assembly, a core engine, a gearbox, and a gearbox efficiency rating. The fan assembly can include a plurality of fan blades. The pitch change mechanism can be coupled to the fan assembly. The vane assembly can include a plurality of vanes. The core engine can include one or more compressor sections and one or more turbine sections. The gearbox includes an input and an output. The input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, the output is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 4.1-14.0. The gearbox efficiency rating is 0.10-1.8.

A turbomachine engine can include a fan assembly, a pitch change mechanism, a vane assembly, a core engine, a gearbox, and a gearbox efficiency rating. The fan assembly can include a plurality of fan blades. The pitch change mechanism can be coupled to the fan assembly. The vane assembly can include a plurality of vanes. The core engine can include one or more compressor sections and one or more turbine sections. The gearbox includes an input and an output. The input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, the output is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 4.1-14.0. The gearbox efficiency rating is 0.10-1.8.

A turbomachine engine can include a fan assembly, a vane assembly, a core engine, a gearbox, and an overall engine efficiency rating. The fan assembly can include a plurality of fan blades. The vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include a low-pressure turbine. The gearbox includes an input and an output. The input of the gearbox is coupled to the low-pressure turbine of the core engine and comprises a first rotational speed, the output of the gearbox is coupled to the fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 3.2-4.0. The overall engine efficiency rating is within a range of 0.57-8.0.

The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.

A gas turbine engine for an aircraft comprises, in axial flow sequence, a compressor module, a combustor module, and a turbine module. The gas turbine engine further comprises a first electric machine that is rotationally connected to the turbine module, and an electrical energy storage unit. The gas turbine engine is configured to generate a maximum dry thrust T (N). The first electric machine is configured to generate a maximum electrical power P.sub.EM1 (W). The electrical energy storage unit has an energy storage capacity E (Wh), a maximum charge rate C (h.sup.−1), and a maximum discharge rate D (h.sup.−1). The electrical energy storage unit is configured to store electrical energy that may be generated by the first electric machine.

An improved system, apparatus and method for estimating thrust from an engine, and more specifically, a system for estimating thrust from strain gauge and accelerometer measurements. At least one strain gauge is mounted on an engine mount to measure strain to estimate a constant velocity or steady-state portion of thrust. At least one accelerometer is mounted on the vehicle to measure acceleration to estimate a transient portion of thrust. Steady-state thrust estimation and transient thrust estimation are combined to estimate thrust from the engine. An algorithm provides steps for estimating thrust from strain gauge and accelerometer measurements.

A turbomachine engine can include an unducted fan assembly, an unducted vane assembly, a core engine, a gearbox, and a gearbox efficiency rating. The unducted fan assembly can include a plurality of fan blades. The unducted vane assembly can include a plurality of vanes, and the vanes can, in some instances, be disposed aft of the fan blades. The core engine can include one or more compressor sections and one or more turbine sections. The gearbox includes an input and an output. The input is coupled to the one or more turbine sections of the core engine and comprises a first rotational speed, the output is coupled to the unducted fan assembly and has a second rotational speed, and a gear ratio of the first rotational speed to the second rotational speed is within a range of 4.1-14.0. The gearbox efficiency rating is 0.10-1.8.

The method can include determining a mass flow rate W of working fluid circulating through the compressor stage, determining a control parameter value associated to the geometrical configuration of the variable geometry element based on the determined value of mass flow rate W; and changing the geometrical configuration of the variable geometry element in accordance with the determined control parameter value.

A turbomachinery includes a casing, a rotor shaft rotatably attached to the casing, a first blade row fixed to either one of the rotor shaft or the casing, and a second blade row fixed to either one of the rotor shaft or the casing and arranged adjacent to the upstream side or downstream side of the first blade row, wherein the turbomachinery sets the number of first blades and the number of second blades in a manner that the interblade phase angle difference of the second blade row is ±180°.