Wind farm
A New Twist Makes Rotating Machinery More Efficient and Quieter
Derived from a design approach for a new wing known as PRANDTL-D, this technology achieves similar improvements for propellers and other rotating machinery. <b><em>How It Works</b></em> To achieve the innovation's alternate spanload, Armstrong designers applied a non-linear twist to the propeller blade. The twist moves the load inward and dissipates the tip vortex over a wider area, minimizing its effect on drag. It also results in a decrease in load at the tip and reduced torque at the tip. These changes combine to achieve a dramatic reduction in power consumption without compromising the blade's other parameters. Specifically, the blade's diameter and rpm remain unchanged. <b><em>What Makes It Better</b></em> Unlike the conventional minimum induced loss (elliptical) spanload, which consumes large amounts of power at the tip of the blade, the new design unloads the tip and reduces torque, achieving significant improvements in efficiency. First-order analysis shows a more than 15 percent improvement in power consumption while producing the same thrust. The design also produces significantly less noise than conventional blade designs.
Example Illustration - Spacecraft with Artificial Gravity Modules
Spacecraft with Artificial Gravity Modules
Conventionally, the approaches of creating artificial gravity in space was envisioned as a large rotating space station that creates an inertial force that mimics the effects of a gravitational force. However, generating artificial gravity with large rotating structures poses problems, including (1) the need to mass balance the entire rotating spacecraft in order to eliminate or minimize rotational imbalance causing gyroscopic precession/nutation motions and other oscillations of the rotating spacecraft; (2) the potentially prohibitive cost, time and schedule to build such a large rotating system; (3) the need to mass balance the spacecraft in real-time so as to minimize passenger discomfort and structural stress on the spacecraft; (4) the difficulty in docking other spacecraft to the rotating spacecraft; (5) the absence or minimal presence of non-rotating structure for 0G research and industrial use; and (6) the generation of extraneous Coriolis effect on spacecraft inhabitants. The novel technology can help solve the problems referenced above and other problems by (1) providing a non-rotating space station or structure, and connecting modules that generate artificial gravity by traveling along a circular path around the non-rotating space station; (2) providing modules that are more easily built and balanced; (3) providing a stationary structure that can provide a platform for other components that do not need gravity to function; (4) providing capability to actively interrogate what levels of mass imbalance are acceptable, for use in determining operational constraints; and (5) reducing or eliminating Coriolis effect on occupants in habitation modules. The concepts of the invention are very cost-effective and allow for building a minimal initial system to produce artificial gravity at the first phases of construction, before the full structure is built. An additional benefit is that construction and assembly of new capabilities can be performed without disrupting the ongoing artificial gravity environment of the existing structure.
mechanical and fluid systems
Reverse Vortex Ring (RVR)
Vibration problems, which occur more frequently in high power to weight machines, often lead to costly down time, subsequent redesign, and, in some instances, catastrophic failure. A disproportionate number of vibration problems in rotating machinery can be attributed to highly pre-swirled fluid entering tight clearance locations such as seals and fluid bearings. The relationship between high fluid pre-swirl and undesirable vibration issues is clear. Machines with high levels of fluid pre-swirl are more susceptible to instabilities and vibration problems. A top priority in rotor dynamic design, therefore, is to develop devices to minimize the level of fluid pre-swirl entering tight clearance locations. The RVR was designed to condition the flow prior to entering the seal (or axial flow fluid-film bearing) so that the flow through the annular clearance is at a minimum purely axial. While conventional swirl brakes have only been shown to reduce pre-swirl by up to 30%, the RVR can actually reverse the direction of the swirl, so that circumferential fluid velocity flows in a direction counter to shaft rotation. Thus, a classic detriment to rotating machinery has now become an asset to ameliorate vibration issues through the RVR. The RVR is axially efficient, typically increasing the axial length of a smooth annular seal on the order of 10-12%. The RVR has been extensively tested and is now in use at NASA.
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