Category Archives: Transportation

Aerospace, automotive, aviation, etc.

Localized Arc Filament Plasma Actuators for Noise Mitigation and Mixing Enhancement

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Summary:

The Ohio State University has developed a new technology that could reduce jet engine noise during takeoff and landing while not affecting the jet exhaust flow and thrust during cruising and thus improving fuel efficiency. Jet noise has been a major issue in commercial subsonic aircraft and in the development of supersonic aircraft for decades. Recently, encroachment of neighboring communities on military airports and landing strips has also created growing pressure to reduce community noise from the military aircraft. Noise radiation from the exhaust jet in an aircraft is the dominant component of noise during takeoff and a major component during landing. While chevrons and tabs have been researched for noise reduction for decades, they were very recently put in use in jet aircraft engines for noise reduction. Since these devices are simple geometric modifications at the nozzle exit, their pattern and strength cannot be changed, and they remain active during the entire flight even when they are not needed. As a result, they decrease the fuel efficiency during most of the fight. This technology utilizes localized arc filament plasma (LAFP) actuators that can be turned on and off as needed, and their pattern and strength can be changed to further reduce jet engine noise and improve fuel efficiency. In addition, LAFP actuators could manipulate instabilities in the jet to maximize their effectiveness.

Potential Applications:

LAFP actuators could be used in jet aircraft engines, large or small, commercial or military, for jet noise reduction.

Advantages:

LAFP actuators can modify the flow field on command and can be turned “on” and “off” to minimize required power and potential losses when actuation is necessary.

This results in:

  • Noise reduction during takeoff and landing
  • Improved fuel efficiency during cruising altitude
  • Manipulation of the jet’s instabilities

In addition:

  • LAFP actuators do not involve any moving parts.
  • LAFP actuators do not change the geometry of the system/vehicle.
  • LAFP actuators can control mixing and noise in the jet by either excitation of the flow instabilities, by generating stream-wise vortices of desired frequency and strength, or by a combination of the two techniques.

Engineered Particulate Reinforcement of Polyimides

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Summary:

Researchers at the Ohio State University have discovered a new way to increase the toughness and the wear of materials by tuning particle characteristics. Plastics are often filled with inexpensive inorganic particles to improve the plastics’ wear and toughness. While it is well-known that these particles can provide significant benefits by simple property averaging, relatively little fine tuning of particle characteristics have taken place.

We have determined that these characteristics can have a dominant effect on the wear and toughness of a given polymer matrix, and this effect can be a more significant factor than the identity of the matrix itself. The results have borne this out: the toughness of a ""tuned"" commercial polyimide, Superimide 800, increased by a factor of ten over the unadulterated material. The large improvement that can be made to existing and new materials by simply fine tuning the characteristics of inorganic particles will have a significant impact on commericial airline, automotive, and other transportation industries that either use or will use polyimides as high temperature lightweight plastics.

Potential Applications:

  • Dentistry
  • Aerospace
  • Biomedical
  • Electronics
  • Automotives

Two-Stage Catalytic System for Nitrogen Oxide Reduction with Methane Under Lean Conditions

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Summary:

The reduction of nitrogen oxides in lean combustion exhaust streams suffers from significant challenges with regard to reducing agent choice. Hydrocarbons are the ideal reducing agent as they are present in the exhaust stream of many applications. We have developed a two-stage catalytic approach, which offers significant improvements in nitric oxide reduction activity for lean exhaust.

Potential Applications:

  • Catalytic aftertreatment of nitric oxide for lean-burn natural gas engines.
  • While the system has been tested using methane as the reducing agent the principles could also be used in other lean combustion applications such as diesel engines.

Advantages:

  • The two-stage approach to nitric oxide reduction allows for a more fundamental understanding of the catalytic phenomena associated with nitric oxide reduction.
  • An improved understanding potentially allows for more customization and improvements to the catalytic system.
  • The use of hydrocarbons present in the exhaust stream completely eliminates fuel penalties associated with nitric oxide reduction.

Super hydrophobic surface profiles

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Summary:

Engineers at The Ohio State University have developed super-slick, water-repellent surfaces that mimic the texture of lotus leaves. Scientists have long known that the lotus, or water lily, provides a good model for studying water-repellent surfaces. In studying this leaf, which is covered with microscopic bumps, OSU’s inventors realized that its texture could be exploited in applications where reduced friction is desired, as water-repellent surfaces generally exhibit a low coefficient of friction. The challenge is in optimizing the surface for specific materials and applications, so the researchers developed the first computer model that calculates the optimal distribution of "bumps" on the surface for a particular application. Among the wide range of potential applications, this technology could lead to self-cleaning glass, and could also reduce friction between the tiny moving parts inside micro-electrical-mechanical systems (MEMS), which can’t be lubricated by traditional means.

Potential Applications:

  • Self-cleaning glass for automotive and building applications
  • Water-repellent textiles/clothing
  • Lubrication of individual parts in MEMS/NEMS devices
  • Replacement of traditional lubrication techniques for a wide class of machine components
  • May reduce aerodynamic drag for automotive/aerospace applications
  • Self-cleaning solar panels

Advantages:

  • Overcomes limitations of traditional lubrication techniques for MEMS/NEMS devices
  • Can be optimized for a particular application
  • Achieves a lower coefficient of friction than the lotus leaf itself

High-Performance, Economically-Viable Membranes for Carbon Dioxide (CO2) Separation

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Summary:

Economically viable removal of CO2 from sources such as coal plant flue gas and gasification mixtures requires affordable separation membranes that have high selectivity combined with high flux. State of the art membranes do not meet these requirements. Researchers at The Ohio State University have developed a new ultrathin inorganic membrane that exhibits high selectivity and a potentially high permeance for the separation of CO2 with respect to other gases. The membrane exhibits long-term stability, and operations over a wide range of temperatures.

Potential Applications:

  • Fuel Cells
  • Power Plants
  • CO2 recovery from fossil fuel combustion sources

Advantages:

  • Achieves both high CO2 selectivity and high flux
  • Can be easily manufactured

A Robust High-Temperature Semiconducting Carbon Monoxide (CO) Sensor

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Summary:

In many combustion-related industries, monitoring CO levels is critical for estimating the efficiency of the combustion process. With the ideal balance of oxygen to fuel, pollution is also minimized. Existing gas sensors based on metal oxide materials typically operate at 200-300 degrees C. Researchers at The Ohio State University have developed a CO sensor for hostile industrial environments (450-800 degrees C) that responds to CO at concentrations approaching one part per million. These sensors can be miniaturized with minimal electrical power requirements, and exhibit stable baseline resistance and good response and recovery times. To the best of our knowledge, we know of no existing solid state sensors that equal the performance of these sensors.

Potential Applications:

  • Combustion control
  • Heat treating
  • Metal processing and casting
  • Glass and ceramics manufacturing
  • Food processing
  • Power plant operations
  • Automotive applications

Advantages:

  • Responds to CO at ppm levels
  • Can be used in high-temperature, hostile environments (450-800 degrees C)
  • Minimal drift
  • Quick recovery times
  • More economical than existing high-temperature sensor technologies

Graphene Composites as the Cathode Material of High-Power Lithium Ion Batteries

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Summary:

Lithium ion batteries, commonly found in today’s mobile devices, are poised to play a major role in serving our future energy needs. While current batteries are suitable for mobile phones and laptops, their energies and power densities are insufficient for more demanding applications such as transportation and mass energy storage. The major limiting factor in lithium ion battery performance is in the cathode material, and various materials have been identified that offer large capacity, low cost, chemical stability, and environmental friendliness. Unfortunately, these materials also suffer from very poor electrical conductivity. Much research has focused on forming composites of these materials with different kinds of carbons, conductive polymers, metals, and oxides in order to alleviate this issue, with little success. Researchers at The Ohio State University have developed composites of these materials with graphene (planar atomic sheets of graphite) that exhibit excellent electrical conductivity while maintaining the beneficial properties noted above. The researchers have developed one type of graphene composite that boosted the electrical conductivity (compared to the material alone) by eight orders of magnitude. Amazingly, in this case graphene only makes up 3.6% of the composite by weight! Other material systems and methods of manufacture have been developed, and continue to be investigated, that could yield even more impressive results.

Potential Applications:

  • High density energy storage for alternative energy sources
  • Transportation (e.g. hybrid and plug-in electric vehicles)
  • Mobile devices (enables much longer life and better performance with a smaller battery)

Advantages:

  • A major breakthrough in the quest for high performance lithium ion batteries with large energy densities
  • Enables an environmentally friendly cathode material that exhibits large capacity, low cost, chemical stability, and high electrical conductivity
  • In one test, adding as little as 3.6% graphene by weight boosted the electrical conductivity of a material by eight orders of magnitude
  • Low carbon content in electrodes due to the use of graphene (3.6% by weight) results in enhanced overall gravimetric and volumetric capacities
  • Exhibits superior rate capability, maintaining ~70% capacity at 20 C

Miniaturizable, High Temperature Oxygen Sensor

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Summary:

In a variety of applications from automobiles to power plants, the optimization of combustion parameters is critical in maximizing efficiency and minimizing harmful emissions.  In fact, it is estimated that yearly savings of over $400 million could be enabled through combustion optimization within coal-fired power plants.  In order to optimize combustion, oxygen levels need to be carefully controlled, which calls for accurate and reliable oxygen sensor technologies.  Such sensor technologies must be able to withstand the high temperatures found in combustion environments while exhibiting the smallest possible footprint.

In order to fulfill this need, researchers at The Ohio State University have developed a miniaturizable, high temperature oxygen sensor that is capable of long-term operation and is resistant to the strains of thermal cycling.  Currently, the sensor can withstand temperatures up to 800 degrees C.  Furthermore, as the sensor does not require reference gas plumbing, there is flexibility in the placement of these sensors in a combustion stream. 

Potential Applications:

  • Automotive
  • Power plants
  • Medical
  • Diving
  • Scientific

Advantages:

  • Cost effective
  • Reliable over long-term operation
  • Can withstand temperatures up to 800 degrees C
  • Miniaturizable
  • Affords flexibility in sensor placement