Periodic Wave Disc Brake Rotor

Mechanical and Fluid Systems
Periodic Wave Disc Brake Rotor (MFS-TOPS-106)
Lightweight brake rotor design with high heat dissipation using novel surface cooling technology
Overview
Developed by innovators at the NASA Marshall Space Flight Center, the Periodic Wave Disc Brake Rotor offers improved performance for potential applications in racings cars, motorcycles, and in particular for electric vehicles (EVs) equipped with regenerative braking systems. NASA's periodic wave rotor technology is a suite of rotor designs that provides dramatic weight reduction along with high heat dissipation, two of the primary challenges associated with high performance braking systems. Increasing any vehicle's racing performance involves decreasing the rotational moment of inertia and brake-system weight, which allow the vehicle to accelerate faster, change direction better, and require less energy when doing all of the above. For racing cars, reducing braking system weight is all about achieving better lap times. For any popular EVs, however, decreased electrical energy expenditure provides increased travel range. NASA's Periodic Wave Disc Brake Rotor can be easily implemented into any existing vehicles with either hub-mounted or wheel rim-mounted brake systems.

The Technology
The NASA Periodic Wave Disc Brake Rotor is novel yet elegantly simple and cost-effective design to maximize weight reduction and heat dissipations. This is accomplished through NASA's proprietary concept of combining the forced convection, radiation, and conduction of air flow over the brake rotor's surface. Depending upon the application, a dramatic reduction of the rotor material itself can be selected from either steel, oxygen-diffused titanium, or an aluminum forging alloy. A two-piece floating rotor assembly is designed to further reduce the weight of the rotor's mounting hub and its rotational moment of inertia, while simultaneously minimizing the rotor's thermal expansion, stress, warping, or distortion experience during extreme frictional heating generated from repeated hard braking actions under high speed racing conditions.
Photo by Juan Rojas, https://unsplash.com/photos/lVDXRLVZyP4
Benefits
  • Lightweight and low-profile: The Periodic Wave Disc Brake Rotor is ~3x lighter and ~2-3x thinner than traditional rotors
  • High-performance, efficient design: NASA's new rotor offers performance comparable to high-end carbon rotors with costs similar to steel rotors currently on the market by cutting mass and reducing the potential for damage from stress and distortion when the rotor is under high thermal load
  • Adaptable design: Design elements can be adapted for a variety of applications, including front and rear rotors for a variety of motor vehicles

Applications
  • Automotive: high-efficiency, lightweight brake rotors for motor vehicles including cars, motorcycles, off-road vehicles, and trucks
  • Electric vehicles: lightweight brake rotors for regenerative braking systems
  • Auto racing: high-performance brakes for racing cars or motorcycles
Technology Details

Mechanical and Fluid Systems
MFS-TOPS-106
MFS-33878-1 MFS-33878-1-CIP
11,441,625 12,117,056
Similar Results
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title
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.
NASA HWB
High-Voltage Power System for Hybrid Electric Aircraft Propulsion
Glenn's novel system supports the NASA Aeronautics Research Mission Directorate (ARMD) strategic plan to leverage advancements in technologies over the next 25 years and beyond, leading to new aircraft configurations with enhanced performance, improved energy efficiency, and reduced CO2 emissions. The electric system is a multi-megawatt micro-grid that converts mechanical energy to electric via generators, and electric energy to mechanical via motor-driven fans. This innovation would use the variation in aircraft throttle settings to produce a high-voltage (20 kilovolts), variable-frequency 9-phase AC distribution system. Using doubly fed electric machines (generator, propulsor, and flywheel) allows for field excitation that can cause variable-frequency or variable speed operation around the commanded throttle setting. The flywheel enables an energy storage system that recovers and reuses energy, while the flywheel slews with the throttle control using the electromagnetic torque produced by the doubly fed electric machine. This design permits both sub-synchronous and super-synchronous operation using limited field excitation power provided through power converters. Finally, the reduced switchgear mass facilitated through the use of a high-frequency AC system, setting-less protection zones, and simplified switches for fault clearance provides enhanced operational capability. This system can be controlled so that fault energy is minimized, preventing collateral damage to aircraft structures even with high voltage distribution. Glenn's innovative system adds performance, efficiency, reliability, and cost savings to cutting-edge hybrid electric technology. This is an early-stage technology requiring additional development, and Glenn welcomes co-development opportunities.
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Source of image, https://commons.wikimedia.org/wiki/File:Compressor_blisk_on_display_(4).jpg
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