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Edward J. Park - One of the best experts on this subject based on the ideXlab platform.

  • Analytical modeling of eddy current brakes with the application of time varying magnetic fields
    Applied Mathematical Modelling, 2016
    Co-Authors: Kerem Karakoc, Afzal Suleman, Edward J. Park
    Abstract:

    Abstract Eddy current brakes have a number of potential advantages, i.e. contactless operation, faster response, reduced number of components and easy implementation of various controllers. However, the Braking Torque generation is limited at low speeds. Here, to increase the Braking Torque generation, time varying field application is studied. A new analytical model is derived for in-depth theoretical analysis and future controller design purposes. The Braking Torque generated is calculated using magnetic vector potential and eddy currents. Then, this model was validated using an accurate finite element model. Results show that the Braking Torque increases with the application of time-varying fields.

  • Optimized Braking Torque generation capacity of an eddy current brake with the application of time-varying magnetic fields
    IEEE Transactions on Vehicular Technology, 2014
    Co-Authors: Kerem Karakoc, Edward Park, Afzal Suleman, Edward J. Park
    Abstract:

    Unlike conventional hydraulic brakes (CHBs), eddy-current brakes (ECBs) are electrically controlled and noncontact-type actuators. Having such advantages makes ECBs a potential alternative to the conventional systems used in vehicles. However, the Braking Torque generation of ECBs at low speed is insufficient to stop the vehicle. Thus, such brakes are used for assistive Braking. Our previous study showed that Braking Torque increases with an ac field application compared with the Torque generated with a dc field application. To increase the Braking Torque generation to realize a stand-alone ECB, the Braking Torque generation of the ECB is optimized, using a stochastic search algorithm, with the consideration of comfort and skin effects, as well as geometric and field-dependent factors. The results show that the application of an ac field with varying frequency on a configuration with multiple pole projection areas (PPAs) results in a significant increase in the Braking Torque compared with the dc field application, and such optimum ECB configuration can generate a sufficient amount of Braking Torque comparable with those generated by CHBs.

  • improved Braking Torque generation capacity of an eddy current brake with time varying magnetic fields a numerical study
    Finite Elements in Analysis and Design, 2012
    Co-Authors: Kerem Karakoc, Edward J. Park, Afzal Suleman
    Abstract:

    Eddy current brakes (ECB) are electrically controlled and non-contact actuators used as assistive brakes in vehicles. ECBs exhibit insufficient generated Braking Torque at low speeds. In order to overcome this, the use of AC magnetic fields with fixed and variable frequencies in different waveforms is investigated at both low and high speeds. Finite element analysis validated by an existing analytical model is performed for DC and AC magnetic fields. In addition, the frequency of the applied field is optimized using genetic algorithms on a generic ECB configuration.

  • design considerations for an automotive magnetorheological brake
    Mechatronics, 2008
    Co-Authors: Kerem Karakoc, Edward J. Park, Afzal Suleman
    Abstract:

    In this paper, design considerations for building an automotive magnetorheological (MR) brake are discussed. The proposed brake consists of multiple rotating disks immersed in a MR fluid and an enclosed electromagnet. When current is applied to the electromagnet, the MR fluid solidifies as its yield stress varies as a function of the magnetic field applied. This controllable yield stress produces shear friction on the rotating disks, generating the Braking Torque. In this work, practical design criteria such as material selection, sealing, working surface area, viscous Torque generation, applied current density, and MR fluid selection are considered to select a basic automotive MR brake configuration. Then, a finite element analysis is performed to analyze the resulting magnetic circuit and heat distribution within the MR brake configuration. This is followed by a multidisciplinary design optimization (MDO) procedure to obtain optimal design parameters that can generate the maximum Braking Torque in the brake. A prototype MR brake is then built and tested and the experimental results show a good correlation with the finite element simulation predictions. However, the Braking Torque generated is still far less than that of a conventional hydraulic brake, which indicates that a radical change in the basic brake configuration is required to build a feasible automotive MR brake.

Kerem Karakoc - One of the best experts on this subject based on the ideXlab platform.

  • Analytical modeling of eddy current brakes with the application of time varying magnetic fields
    Applied Mathematical Modelling, 2016
    Co-Authors: Kerem Karakoc, Afzal Suleman, Edward J. Park
    Abstract:

    Abstract Eddy current brakes have a number of potential advantages, i.e. contactless operation, faster response, reduced number of components and easy implementation of various controllers. However, the Braking Torque generation is limited at low speeds. Here, to increase the Braking Torque generation, time varying field application is studied. A new analytical model is derived for in-depth theoretical analysis and future controller design purposes. The Braking Torque generated is calculated using magnetic vector potential and eddy currents. Then, this model was validated using an accurate finite element model. Results show that the Braking Torque increases with the application of time-varying fields.

  • Optimized Braking Torque generation capacity of an eddy current brake with the application of time-varying magnetic fields
    IEEE Transactions on Vehicular Technology, 2014
    Co-Authors: Kerem Karakoc, Edward Park, Afzal Suleman, Edward J. Park
    Abstract:

    Unlike conventional hydraulic brakes (CHBs), eddy-current brakes (ECBs) are electrically controlled and noncontact-type actuators. Having such advantages makes ECBs a potential alternative to the conventional systems used in vehicles. However, the Braking Torque generation of ECBs at low speed is insufficient to stop the vehicle. Thus, such brakes are used for assistive Braking. Our previous study showed that Braking Torque increases with an ac field application compared with the Torque generated with a dc field application. To increase the Braking Torque generation to realize a stand-alone ECB, the Braking Torque generation of the ECB is optimized, using a stochastic search algorithm, with the consideration of comfort and skin effects, as well as geometric and field-dependent factors. The results show that the application of an ac field with varying frequency on a configuration with multiple pole projection areas (PPAs) results in a significant increase in the Braking Torque compared with the dc field application, and such optimum ECB configuration can generate a sufficient amount of Braking Torque comparable with those generated by CHBs.

  • improved Braking Torque generation capacity of an eddy current brake with time varying magnetic fields a numerical study
    Finite Elements in Analysis and Design, 2012
    Co-Authors: Kerem Karakoc, Edward J. Park, Afzal Suleman
    Abstract:

    Eddy current brakes (ECB) are electrically controlled and non-contact actuators used as assistive brakes in vehicles. ECBs exhibit insufficient generated Braking Torque at low speeds. In order to overcome this, the use of AC magnetic fields with fixed and variable frequencies in different waveforms is investigated at both low and high speeds. Finite element analysis validated by an existing analytical model is performed for DC and AC magnetic fields. In addition, the frequency of the applied field is optimized using genetic algorithms on a generic ECB configuration.

  • design considerations for an automotive magnetorheological brake
    Mechatronics, 2008
    Co-Authors: Kerem Karakoc, Edward J. Park, Afzal Suleman
    Abstract:

    In this paper, design considerations for building an automotive magnetorheological (MR) brake are discussed. The proposed brake consists of multiple rotating disks immersed in a MR fluid and an enclosed electromagnet. When current is applied to the electromagnet, the MR fluid solidifies as its yield stress varies as a function of the magnetic field applied. This controllable yield stress produces shear friction on the rotating disks, generating the Braking Torque. In this work, practical design criteria such as material selection, sealing, working surface area, viscous Torque generation, applied current density, and MR fluid selection are considered to select a basic automotive MR brake configuration. Then, a finite element analysis is performed to analyze the resulting magnetic circuit and heat distribution within the MR brake configuration. This is followed by a multidisciplinary design optimization (MDO) procedure to obtain optimal design parameters that can generate the maximum Braking Torque in the brake. A prototype MR brake is then built and tested and the experimental results show a good correlation with the finite element simulation predictions. However, the Braking Torque generated is still far less than that of a conventional hydraulic brake, which indicates that a radical change in the basic brake configuration is required to build a feasible automotive MR brake.

Afzal Suleman - One of the best experts on this subject based on the ideXlab platform.

  • Analytical modeling of eddy current brakes with the application of time varying magnetic fields
    Applied Mathematical Modelling, 2016
    Co-Authors: Kerem Karakoc, Afzal Suleman, Edward J. Park
    Abstract:

    Abstract Eddy current brakes have a number of potential advantages, i.e. contactless operation, faster response, reduced number of components and easy implementation of various controllers. However, the Braking Torque generation is limited at low speeds. Here, to increase the Braking Torque generation, time varying field application is studied. A new analytical model is derived for in-depth theoretical analysis and future controller design purposes. The Braking Torque generated is calculated using magnetic vector potential and eddy currents. Then, this model was validated using an accurate finite element model. Results show that the Braking Torque increases with the application of time-varying fields.

  • Optimized Braking Torque generation capacity of an eddy current brake with the application of time-varying magnetic fields
    IEEE Transactions on Vehicular Technology, 2014
    Co-Authors: Kerem Karakoc, Edward Park, Afzal Suleman, Edward J. Park
    Abstract:

    Unlike conventional hydraulic brakes (CHBs), eddy-current brakes (ECBs) are electrically controlled and noncontact-type actuators. Having such advantages makes ECBs a potential alternative to the conventional systems used in vehicles. However, the Braking Torque generation of ECBs at low speed is insufficient to stop the vehicle. Thus, such brakes are used for assistive Braking. Our previous study showed that Braking Torque increases with an ac field application compared with the Torque generated with a dc field application. To increase the Braking Torque generation to realize a stand-alone ECB, the Braking Torque generation of the ECB is optimized, using a stochastic search algorithm, with the consideration of comfort and skin effects, as well as geometric and field-dependent factors. The results show that the application of an ac field with varying frequency on a configuration with multiple pole projection areas (PPAs) results in a significant increase in the Braking Torque compared with the dc field application, and such optimum ECB configuration can generate a sufficient amount of Braking Torque comparable with those generated by CHBs.

  • improved Braking Torque generation capacity of an eddy current brake with time varying magnetic fields a numerical study
    Finite Elements in Analysis and Design, 2012
    Co-Authors: Kerem Karakoc, Edward J. Park, Afzal Suleman
    Abstract:

    Eddy current brakes (ECB) are electrically controlled and non-contact actuators used as assistive brakes in vehicles. ECBs exhibit insufficient generated Braking Torque at low speeds. In order to overcome this, the use of AC magnetic fields with fixed and variable frequencies in different waveforms is investigated at both low and high speeds. Finite element analysis validated by an existing analytical model is performed for DC and AC magnetic fields. In addition, the frequency of the applied field is optimized using genetic algorithms on a generic ECB configuration.

  • design considerations for an automotive magnetorheological brake
    Mechatronics, 2008
    Co-Authors: Kerem Karakoc, Edward J. Park, Afzal Suleman
    Abstract:

    In this paper, design considerations for building an automotive magnetorheological (MR) brake are discussed. The proposed brake consists of multiple rotating disks immersed in a MR fluid and an enclosed electromagnet. When current is applied to the electromagnet, the MR fluid solidifies as its yield stress varies as a function of the magnetic field applied. This controllable yield stress produces shear friction on the rotating disks, generating the Braking Torque. In this work, practical design criteria such as material selection, sealing, working surface area, viscous Torque generation, applied current density, and MR fluid selection are considered to select a basic automotive MR brake configuration. Then, a finite element analysis is performed to analyze the resulting magnetic circuit and heat distribution within the MR brake configuration. This is followed by a multidisciplinary design optimization (MDO) procedure to obtain optimal design parameters that can generate the maximum Braking Torque in the brake. A prototype MR brake is then built and tested and the experimental results show a good correlation with the finite element simulation predictions. However, the Braking Torque generated is still far less than that of a conventional hydraulic brake, which indicates that a radical change in the basic brake configuration is required to build a feasible automotive MR brake.

Juliusz Gajewski - One of the best experts on this subject based on the ideXlab platform.

  • zddp content in mineral and synthetic motor base oils and its effect on electrostatic and tribological phenomena in a rotating shaft oil lip seal system
    Tribology International, 2010
    Co-Authors: Juliusz Gajewski, Kazimierz Gatne, Marek J Głogowski, Marek Gawlinski
    Abstract:

    Abstract The paper presents the results of experiments on electrostatic and tribological aspects of different ZDDP (zinc dialkyldithiophosphate) contents when ZDDP is added to different mineral and synthetic motor base oils. Experiments were carried out in a rotating shaft–oil–lip seal system which is an experimental facility in whose interior a metal shaft rotated at given angular velocities, and where the level of tribocharging in the interfacial system was measured. The Braking Torque of a shaft was also measured. The Braking Torque generally decreased when an external DC electric field was applied to the system.

  • interpretation of the results of research on tribocharging in a rotating shaft oil lip seal system
    Journal of Electrostatics, 2009
    Co-Authors: Juliusz Gajewski, Kazimierz Gatne
    Abstract:

    Abstract A rotating shaft, rotary lip seal, and oil creating a film between the surfaces of a shaft and of a lip of the seal sets up a system, which is relatively simple geometrically, but complex physically and electrochemically. Such a system is characteristic of all machinery, engines, etc. where rotating parts and seals occur. In the experiments and tests performed to date different real commercial motor oils, original base oils, additives to base oils (antiwear and extreme pressure additives), lip seals, and shafts with different roughness have been used for a range of oil temperatures and shaft angular velocities. Tribocharging in the interfacial system: rotating shaft–oil–lip seal (the friction junction) is observed and analysed. Other experiments were performed to compensate for the electric field generated in the system applying an external DC electric field and to find its effect on friction and the Braking Torque of the shaft. The results show that tribocharging can exert influence on the Braking Torque of a rotating shaft. The reduction of the Braking Torque under the action of an external DC electric field is also observed. The similar experiments are repeated with the use of pure base oils and additives including zinc dialkyldithiophosphate (ZDDP). Tribocharging is evident in the case of pure base oils and when these are blended with ZDDP. The external DC electric field also reduces the Braking Torque while applying the DC voltage to the system. Here the authors try to interpret the former and last research results in their physical aspect and to answer some questions.

  • electrostatic and tribological phenomena and their effect on the Braking Torque in the shaft oil lip seal system
    Journal of Physics: Conference Series, 2008
    Co-Authors: Juliusz Gajewski, Marek J Glogowski
    Abstract:

    The former research [1] was carried out on the influence of tribocharging in a system: metal rotating shaft-oil-lip seal on its work, especially on changes in the shaft Braking Torque with the increasing angular shaft velocity and oil temperature. The results obtained suggested that there be a possibility of reducing the Braking Torque by an external electric field. The compensation for the electric field generated in the system by natural tribocharging was proposed. The reduction in the Braking Torque seemed possible while applying an external DC electric field to the system. In general, the Torque tended to increase with the increasing DC electric field for a variety of the oils and lip seals used and for different shaft angular velocities (rotational speeds) and oil temperatures. The Braking Torque reduction was achieved only for one lip seal and some different oils, which was and is a promising, expected result. The research results were yet presented elsewhere [1–3] and here some novel attempt has been made to interpret the results obtained in their physical—tribological and especially electrostatic—aspects since there has been a lack of such an interpretation in the literature of the subject.

Marek Gawlinski - One of the best experts on this subject based on the ideXlab platform.