Abstract: Embodiments are directed to tiered data store with persistent layers. A write tier in the file system for storing in a file system. A value for a performance metric that corresponds to write requests to the file system may be predicted based on characteristics of the write requests such that the performance metric may be determined based on a plurality of interactions with the write tier. The predicted value that exceeds a threshold value of the performance metric may be employed to cause performance of further actions, including: queuing a portion of the write requests in a memory buffer based on the predicted value and the threshold value; combining the queued portion of the write requests into s; storing the data segments in the write tier such that a measured value of the performance metric may be less than the threshold value.

Abstract: A Method and Test Component for Rotatable Discs Rotatable discs combined with turbine blades in engines must be tested for critical life analysis. Thus, consideration must be made as to life expectancy for such components as a result of tensile circumferential hoops as generated by the weight of blades under rotation as well as compressive axial stress as a result of thermal gradients during initial warm up. Previous testing arrangements have considered tensile circumferential hoop stress but not compressive axial stress combinations such as “Von Mises” stress. By provision of bend structures 13, 223 a bending moment is created about a base 2, 22 formed in a test component 1, 21 such that a bending moment force 4, 24 creates a bending moment in the test component 1, 21. This bending moment results in a compressive axial stress reminiscent of that in a practical turbine engine disc as a result of initial thermal gradients.

Abstract: An apparatus (10) for testing attachment features (26,28,30,32) of components (12,14) comprises a first member (16) having a first end (18), a second end (20), a first edge (22) and a second edge (24). The first edge (22) has a first firtree slot (26) to receive a first component (12) and the second edge (24) has a second firtree slot (28) to receive a second component (14). The first component (12) has a firtree attachment feature (30) to fit the first slot (26) and the second component (14) has a firtree attachment feature (32) to fit the second slot (28). The first end (18) of the first member (16) has flanges (34,36) extending laterally and the second end (20) of the first member (16) has flanges (38,40) extending laterally such that the first member (16) is substantially H-shaped in cross-section.

Abstract: A casing arrangement (20) for surrounding a rotary component (16) of a gas turbine engine (10) is disclosed. The casing arrangement (20) comprises a casing member (22A), which is formed to extend at least partially around the component (16). The casing member (22A) defines a fluid flow path for the flow of a cooling fluid therethrough.

Abstract: A stage of gas turbine engine turbine blades (22) is surrounded by segments (26) that in turn, are suspended from a flexible casing (24). The inner surface of casing (24) is exposed to compressor flow. On engine thrust being increased, compressor output also increases and rapidly flexes casing (24) radially outwards, thus equally rapidly moving the segments (24) away from the tips of the turbine blades (22).

Abstract: The gate arrangement 11 is provided in order to regulate coolant airflow in a path typically in a turbine blade 1 of a jet engine. The gate arrangement 11 includes a gate component 12 having an opening end 15 which at low temperature is closed by a gate member 14. Due to different Coefficients of expansion between the gate component 12 and the gate member 14 when the arrangement 11 increases in temperature there is a divergence between a seal end 21 of the gate member 14 in order to open the opening end 15 of the gate component 12 and to allow coolant airflow through the arrangement 11. Thus, coolant airflow is allowed for high temperatures but as the gate component 12 and gate member 14 converge at sustained typically lower temperatures coolant airflow is stopped in order to prevent unnecessary cooling and so provide greater thermal efficiency.