1. A method of manufacturing a rotatable turbine engine component, the component having a direction of maximum tensile stress during normal engine operation, comprising the steps of:
providing a plurality of biased ceramic plies, each biased ply comprising ceramic fiber tows, the tows woven in a first warp direction and a second weft direction, the second weft direction lying at a preselected angular orientation with respect to the first warp direction, wherein a greater number of tows are woven in the first warp direction than in the second weft direction, and wherein a number of tows in the second weft direction allows the biased plies to maintain their structural integrity when handled;
laying up the plurality of biased plies in a preselected arrangement to form a rotatable component shape, wherein a preselected number of the plurality of biased plies are oriented such that the orientation of the first warp direction of a preselected number of the plurality of biased plies lie about in the direction of maximum tensile stress during normal engine operation, wherein normal engine operation includes rotation of the rotatable turbine engine component;
rigidizing the component shape with a layer of BN and a layer of SiC to form a coated component preform using chemical vapor infiltration;
partially densifying the coated component preform using carbon-containing slurry; and
further densifying the coated component preform with at least silicon to form a rotatable ceramic matrix composite aircraft engine component with biased architecture.
2. The method of claim 1, wherein a ratio of a number of tows in the first warp direction to the number of tows in the second weft direction is at least about 2:1.
3. The method of claim 1, wherein the plies are silicon carbide containing plies.
4. The method of claim 2, wherein the turbine engine component is a turbine blade.
5. The method of claim 2, wherein the turbine engine component is a cooled turbine nozzle.
6. The method of claim 2, wherein the turbine engine component is an uncooled turbine nozzle.
7. A method of manufacturing a rotatable ceramic matrix composite aircraft engine component, the component having a direction of maximum tensile stress during normal engine operation, comprising the steps of:
providing a plurality of prepreg ceramic plies, the plies comprising prepreg ceramic fiber tows, the tows in each ply lying adjacent to one another in a planar arrangement such that each ply has a unidirectional orientation;
laying up the plurality of prepreg ceramic cloth plies in a preselected arrangement to form a rotatable turbine blade shape such that a preselected number of outermost plies are oriented at about 0\xb0 with respect to the direction of maximum tensile stress of the turbine engine component during normal engine operations wherein normal engine operation includes rotation of the rotatatable turbine engine component;
heating the turbine blade shape to form a ceramic preform; and
densifying the turbine blade preform with at least silicon to form a rotatable ceramic matrix composite turbine blade.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of dispensing a volatile material for an operating cycle the method comprising the steps of:
providing power to a volatile material diffuser having a diffusion element;
operating the diffusion element for a first period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a first duty cycle having a first on time and a first off time;
operating the diffusion element for a final period of time, wherein the diffusion element is continuously activated and deactivated during the final period of time at a final duty cycle having a final on time and a final off time; and
ending the operating cycle after the final period of time;
wherein the operating cycle comprises the first period of time and the final period of time, the first duty cycle is less than about 100% such that the first off time is greater than about 0 seconds and the final duty cycle is about 100% such that the final off time is about 0 seconds and wherein the final period of time begins after the first period of time has finished and the final period of time comprises at least about 60% of a total time of the operating cycle.
2. The method of claim 1, wherein the first duty cycle is about 20% and the first period of time is about 5 hours.
3. The method of claim 2, further including the steps of:
operating the diffusion element for a seventh period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a seventh duty cycle;
operating the diffusion element for a eight period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a eight duty cycle; and
operating the diffusion element for a ninth period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a ninth duty cycle.
4. The method of claim 3, wherein the first duty cycle is about 10%, the second duty cycle is about 20%, the third duty cycle is about 30%, the fourth duty cycle is about 40%, the fifth duty cycle is about 50%, the sixth duty cycle is about 60%, the seventh duty cycle is about 70%, the eight duty cycle is about 80%, and the ninth duty cycle is about 90%.
5. The method of claim 4, wherein the first period of time is about 24 hours, the second period of time is about 24 hours, the third period of time is about 96 hours, the fourth, fifth, sixth, seventh, eight, and ninth periods of time are about 48 hours, and the final period of time is about 648 hours.
6. The method of claim 1, wherein the first duty cycle is about 10% and the first period of time is about 24 hours.
7. The method of claim 1, further including the steps of:
operating the diffusion element for a second period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a second duty cycle;
operating the diffusion element for a third period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a third duty cycle;
operating the diffusion element for a fourth period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a fourth duty cycle;
operating the diffusion element for a fifth period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a fifth duty cycle; and
operating the diffusion element for a sixth period of time, wherein the diffusion element is continuously activated and deactivated during the period of time at a sixth duty cycle.
8. The method of claim 7, wherein the first duty cycle is about 20%, the second duty cycle is about 33%, the third duty cycle is about 50%, the fourth duty cycle is about 66%, the fifth duty cycle is about 80%, and the sixth duty cycle is about 90%.
9. The method of claim 8, wherein the first time period is about 5 hours, the second time period is about 5 hours, the third time period is about 14 hours, the fourth time period is about 96 hours, the fifth time period is about 120 hours, the sixth time period is about 120 hours, and the final time period is about 720 hours.
10. A method of dispensing a volatile material, the method comprising the steps of:
providing power to a volatile material diffuser having a diffusion element;
operating the diffusion element for a first period of time, wherein the diffusion element is continuously activated and deactivated during the first period of time at a first duty cycle;
interrupting operation of the diffusion element during the first period of time to operate the diffusion element at a second duty cycle for an interrupt period of time; and
resuming operation of the diffusion element at the first duty cycle after the interrupt period of time;
wherein the first duty cycle is greater than 0% and less than 100% and the second duty cycle is 100%.
11. The method of claim 10, further including the step of returning to the method of claim 10 after the interrupt period if time and continuing operation from a point at which operation was interrupted.
12. The method of claim 10, wherein the second duty cycle is 100%.
13. The method of claim 10, wherein the interrupt period of time is between about 5 minutes and about 4 hours.
14. The method of claim 13, wherein the step of interrupting occurs after a random period of time.
15. A method of dispensing a volatile material, the method comprising the steps of:
providing power to a volatile material diffuser having a diffusion element;
generating a random number using a random number generator;
multiplying the random number by a time factor to determine a first period of time;
operating the diffusion element for the first period of time, wherein the diffusion element is continuously activated and deactivated during the first period of time at a first duty cycle;
interrupting operation of the diffusion element during the first period of time to operate the diffusion element at a second duty cycle for an interrupt period of time; and
resuming operation of the diffusion element at the first duty cycle after the interrupt period of time;
wherein during the first period of time when the first duty cycle is utilized, the diffusion element is alternatingly turned on and off with the on periods being greater than 0% and less than 100% and, during the interrupt period of time when the second duty cycle is utilized, the diffusion element is continuously on.
16. The method of claim 15, wherein the interrupt period of time is between about 5 minutes and about 4 hours.
17. The method of claim 16, wherein the step of interrupting is repeated at least once.