Big Ass Fans
Big Ass Fans entered the commercial business market in 2008, debuting a line of fans ranging from to in diameter. The following year, it began manufacturing fans in sizes suitable for residential settings. In late 2011, Big Ass Fans acquired a manufacturer of energy efficient residential fans. Haiku models incorporate direct current, permanent magnetics and aerodynamic airfoils making them 80% more efficient than conventional ceiling fans. They held the top 10 spots on Energy Star's Most Efficient 2014 list. In 2014, the company added smart technology SenseME to the Haiku ceiling fan. Haiku with SenseME integrates with the Nest Learning Thermostat through a smartphone app.
General Electric GE9X
The GE9X should increase fuel efficiency by 10% over the GE90. Its 61:1 overall pressure ratio should help provide a 5% lower thrust specific fuel consumption (TSFC) than the XWB-97 with maintenance costs comparable to the GE90-115B The initial thrust of will be followed by derated variants.
GE invested more than $2 billion for its development, its nacelle is wide.
Most efficiency increase comes from the better propulsion efficiency of the higher-bypass-ratio fan. The bypass ratio is planned for 10:1. The fan diameter is . It has only 16 blades, whereas the GE90 has 22 and the GEnx has 18. This makes the engine lighter, and allows the low pressure (LP) fan and booster to spin faster to better match its speed with the LP turbine. The fan blades feature steel leading edges and glass-fibre trailing edges to better absorb bird impacts with more flexibility than carbon fiber. Fourth generation carbon fiber composite materials, comprising the bulk of the fan blades, make them lighter, thinner, stronger, and more efficient. Using a composite fan case will also reduce weight.
The high pressure (HP) compressor is up to 2% more efficient. As the GE90 fan left little room to improve the bypass ratio, GE looked for additional efficiency by upping the overall pressure ratio from 40 to 60, focusing on boosting the high-pressure core's ratio from 19:1 to 27:1 by using 11 compressor stages instead of 9 or 10, and a third-generation, twin-annular pre-swirl (TAPS) combustor instead of the previous dual annular combustor. Able to endure hotter temperatures, ceramic matrix composites (CMC) are used in two combustor liners, two nozzles, and the shroud up from the CFM International LEAP stage 2 turbine shroud. CMCs are not used for the first-stage turbine blades, which have to endure extreme heat and centrifugal forces. These are improvements planned for the next iteration of engine technology.
The first-stage HP turbine shroud, the first- and second-stage HP turbine nozzles and the inner and outer combustor linings are made from CMCs, only static components, operating hotter than nickel alloys with some cooling. CMCs have twice the strength and one-third the weight of metal. The compressor is designed with 3D aerodynamics and its first five stages are blisks, combined bladed-disk. The combustor is lean burning for greater efficiency and 30% NOx margin to CAEP/8. The compressor and high pressure turbine are made from powdered metal. The low-pressure turbine airfoils made of titanium aluminide (TiAl) are stronger, lighter, and more durable than nickel-based parts. 3D printing is used to manufacture parts that would otherwise be impossible to make using traditional manufacturing processes. CMCs need 20% less cooling.