Application of optimization techniques to vehicle design: A review

The work that has been done in the last decade or so in the application of optimization techniques to vehicle design is discussed. Much of the work reviewed deals with the design of body or suspension (chassis) components for reduced weight. Also reviewed are studies dealing with system optimization problems for improved functional performance, such as ride or handling. In reviewing the work on the use of optimization techniques, one notes the transition from the rare mention of the methods in the 70's to an increased effort in the early 80's. Efficient and convenient optimization and analysis tools still need to be developed so that they can be regularly applied in the early design stage of the vehicle development cycle to be most effective. Based on the reported applications, an attempt is made to assess the potential for automotive application of optimization techniques. The major issue involved remains the creation of quantifiable means of analysis to be used in vehicle design. The conventional process of vehicle design still contains much experience-based input because it has not yet proven possible to quantify all important constraints. This restraint on the part of the analysis will continue to be a major limiting factor in application of optimization to vehicle design

Transportation noise pollution - Control and abatement

Control and abatement of transportation noise pollutio

Review of ride quality technology needs of industry and user groups

A broad survey of ride quality technology state-of-the-art and a review of user evaluation of this technology were conducted. During the study 17 users of ride quality technology in 10 organizations representing land, marine and air passenger transportation modes were interviewed. Interim results and conclusions of this effort are reported

Effect Stress and Vibration Analysis at NACA Airfoil towards Axial Fan Blade Performance

Axial fans are widely applied in the industrial sector. Axial fans are used for ventilation systems and other cooling systems. The blade design of the axial fan requires an airfoil study. Unfortunately, there are not many articles that discuss in detail about airfoils, especially on noise and vibration that can have an impact on axial fan performance using computational fluid methods or software. This study performs axial fan analysis using computational methods with ANSYS Fluent, Static Structural, Modal and Harmonic Response software to obtain the values of stress, vibration and fluid flow. The experimental design used is using NACA 1412, 4142, and 6412 airfoils on the tip with variations in angles of 60, 74, and 80. While on the hub uses NACA 9312, 9412, and 9512 airfoils with angle variations of 20, 30, and 60 and simulated to find the value of vibration and stress analysis. The 3D axial fan design is imported into the ANSYS Fluent, Static Structural, Modal and Harmonic Response software. The simulation results using Ansys Fluent, shows the pressure contour with a maximum value of 198.424 Pa and Velocity streamline with a maximum value of 28.8669 m/s. the results of the Ansys Static Structural simulation show that the average total deformation is 9.9275e-008 m. The simulation results using Ansys Modal, show that there is a natural frequency of 287.8 Hz and the simulation results of Ansys Harmonic Response obtained an average total deformation of 5.0809e-012 m and the equivalent stress value with a maximum value of σ y, max = 0.20186 Pa

Venting in the comparative study of flexural ultrasonic transducers to improve resilience at elevated environmental pressure levels

The classical form of a flexural ultrasonic transducer is a piezoelectric ceramic disc bonded to a circular metallic membrane. This ceramic induces vibration modes of the membrane for the generation and detection of ultrasound. The transducer has been popular for proximity sensing and metrology, particularly for industrial applications at ambient pressures around 1 bar. The classical flexural ultrasonic transducer is not designed for operation at elevated pressures, such as those associated with natural gas transportation or petrochemical processes. It is reliant on a rear seal which forms an internal air cavity, making the transducer susceptible to deformation through pressure imbalance. The application potential of the classical transducer is therefore severely limited. In this study, a venting strategy which balances the pressure between the internal transducer structure and the external environment is studied through experimental methods including electrical impedance analysis and pitch-catch ultrasound measurement. The vented transducer is compared with a commercial equivalent in air towards 90 bar. Venting is shown to be viable for a new generation of low cost and robust industrial ultrasonic transducers, suitable for operation at high environmental pressure levels

Community rotorcraft air transportation benefits and opportunities

Information about rotorcraft that will assist community planners in assessing and planning for the use of rotorcraft transportation in their communities is provided. Information useful to helicopter researchers, manufacturers, and operators concerning helicopter opportunities and benefits is also given. Three primary topics are discussed: the current status and future projections of rotorcraft technology, and the comparison of that technology with other transportation vehicles; the community benefits of promising rotorcraft transportation opportunities; and the integration and interfacing considerations between rotorcraft and other transportation vehicles. Helicopter applications in a number of business and public service fields are examined in various geographical settings

Piezoelectric and Magnetoelectric Thick Films for Fabricating Power Sources in Wireless Sensor Nodes

In this manuscript, we review the progress made in the synthesis of thick film-based piezoelectric and magnetoelectric structures for harvesting energy from mechanical vibrations and magnetic field. Piezoelectric compositions in the system Pb(Zr,Ti)O3–Pb(Zn1/3Nb2/3)O3 (PZNT) have shown promise for providing enhanced efficiency due to higher energy density and thus form the base of transducers designed for capturing the mechanical energy. Laminate structures of PZNT with magnetostrictive ferrite materials provide large magnitudes of magnetoelectric coupling and are being targeted to capture the stray magnetic field energy. We analyze the models used to predict the performance of the energy harvesters and present a full system description

Paper Session II-C - High-Resolution Integrated Micro Gyroscope for Space Applications

In this paper, an integrated capacitive gyroscope fabricated by CMOS-MEMS technology is presented. The CMOS-compatibility of the fabrication process enables full integration of the sensor with interface and signal conditioning circuitry on a single chip. The entire microstructure is single-crystal silicon based, resulting in large proof mass and good mechanical behaviors. Thus, high-resolution and high-robustness microgyroscopes can be obtained. With a resolution of about 0.01°/s/Hz112 , the fabricated gyroscope chip is only as small as 1.5mm by 2mm including the sensing elements and integrated electronics. The robustness, light weight and high performance make this type of MEMS gyroscope very suitable for space navigation applications where payload is critical. The on-chip capacitive sensing circuitry employs chopper stabilization technique to minimize the influence of 1/f noise. The on-chip circuits also include a two-stage fully differential amplifier and a DC feedback loop to cancel the DC offset. The CMOS fabrication was performed through MOSIS by using the 4-metal TSMC 0.35 μm CMOS process. The post-CMOS micromachining processing consists of only dry etch steps and uses the interconnect metal layers as etching masks. Single-crystal silicon (SCS) structures are produced by applying a backside etch and forming a 60μm-thick SCS membrane. This work is sponsored by NASA through the UCF/UF Space Research Initiative