Centrifugally Pumped Thermosiphons for Motor Rotor Cooling

2015 ◽  
Author(s):  
S. A. McElhinney ◽  
T. M. Jahns ◽  
T. A. Shedd
Keyword(s):  
Cost Effective ◽  
Nucleate Boiling ◽  
Electric Machine ◽  
Operating Conditions ◽  
Synchronous Machines ◽  
Condenser Section ◽  
Torque Density ◽  
Wide Range ◽  
Manufacturing Techniques ◽  
Electric Machine Design

This paper presents a detailed approach to provide improved cooling and heat spreading in electric machine rotors using centrifugally-pumped revolving thermosiphons. Design concepts are discussed that offer the following advantages: (1) high thermal performance across a wide range of operating points; (2) low-impedance heat paths; (3) excellent opportunities for integration with electric machine design for improved electromagnetic performance and structural design, as well as practical, cost-effective manufacturing. It takes advantage of centrifugal force to provide effective inertial pumping over a wide range of operating conditions. In addition, the new thermosiphon design is compatible with existing standard electric machine manufacturing techniques and cooling needs. A condenser section fin and ramp structure provides consistently high condensation performance. Surface texture design to promote effective nucleate boiling at high speeds is discussed, and fluid fill factor is analyzed. Applications include induction and PM synchronous machines. Benefits of these thermosiphons include increased steady-state power and torque density, increased and more consistent efficiency, and reduced permanent magnet volume and cost in PM synchronous machines. Other applications may include centrifugal gas compression, chemical processes, and machine tools.

The Impact of the Surface Shape of the Piston on Power Losses

2014 ◽  
Author(s):  
Ashley M. Wondergem ◽  
Monika Ivantysynova
Keyword(s):  
Energy Dissipation ◽  
Cost Effective ◽  
Operating Conditions ◽  
Surface Shape ◽  
Critical Gap ◽  
Piston Cylinder ◽  
Wide Range ◽  
Load Carrying ◽  
Gap Height ◽  
The Impact

Axial piston machines are widely used in industry thus new cost-effective and highly efficient designs are needed. One way to increase efficiency and decrease cost is by altering the geometry along with the configuration of the piston/cylinder interface influencing the fluid film generation and in turn the energy dissipation and load carrying capacity while still having a design that is cost effective and easy to manufacture. This paper presents a study on a reduction of energy dissipation between the piston and cylinder over a wide range of operating conditions at both full and partial displacements based on the surface shape of the piston along with the minimum clearance. First, it is necessary to measure a base design and then compare those results to simulations in order to verify the simulation results. Once a baseline is established, various piston surface shapes and minimum clearances are then also simulated and compared back to the simulated baseline. Not only is energy dissipation important to compare, but also the minimum gap height over one revolution. The minimum gap height is in direct correlation to friction loss and wear. Therefore, this paper also includes an understanding of how the gap height affects the total losses thus leading to the importance of finding a relative clearance that satisfies a median between torque losses and leakage along with the importance of reducing the occurrence of critical gap heights to reduce the need for wear in in the machine.

scholarly journals Green Synthesis of Metallic Nanoparticles: Applications and Limitations

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 902
Author(s):  
Pritam Kumar Dikshit ◽  
Jatin Kumar ◽  
Amit K. Das ◽  
Soumi Sadhu ◽  
Sunita Sharma ◽  
...  
Keyword(s):  
Green Synthesis ◽  
Metallic Nanoparticles ◽  
Environmental Science ◽  
Cost Effective ◽  
Operating Conditions ◽  
Synthesis Methods ◽  
Comprehensive Overview ◽  
Factors Affecting ◽  
Wide Range ◽  
Range Of Functions

The past decade has witnessed a phenomenal rise in nanotechnology research due to its broad range of applications in diverse fields including food safety, transportation, sustainable energy, environmental science, catalysis, and medicine. The distinctive properties of nanomaterials (nano-sized particles in the range of 1 to 100 nm) make them uniquely suitable for such wide range of functions. The nanoparticles when manufactured using green synthesis methods are especially desirable being devoid of harsh operating conditions (high temperature and pressure), hazardous chemicals, or addition of external stabilizing or capping agents. Numerous plants and microorganisms are being experimented upon for an eco–friendly, cost–effective, and biologically safe process optimization. This review provides a comprehensive overview on the green synthesis of metallic NPs using plants and microorganisms, factors affecting the synthesis, and characterization of synthesized NPs. The potential applications of metal NPs in various sectors have also been highlighted along with the major challenges involved with respect to toxicity and translational research.

A Cost-Effective Active Single Axis Solar Tracking Mechanism Based on Weight Imbalance Principle

2018 ◽  
Author(s):  
A. M. Kader ◽  
Muhammad I. Rashad ◽  
Mahmoud Elzouka ◽  
B. M. El-Souhily
Keyword(s):  
Power Consumption ◽  
Tracking System ◽  
Cost Effective ◽  
Operating Conditions ◽  
Solar Photovoltaic ◽  
Photovoltaic Panel ◽  
Photovoltaic Panels ◽  
Solar Tracking ◽  
Wide Range ◽  
Energy Independence

Solar trackers are rising in popularity; they benefit a wide range of applications since distributed solar energy generation can reduce electricity costs and support energy independence. In this paper, a simple solar tracking system is introduced. The system is a package unit that can be mounted on any solar panel. The system consists of an electrical motor connected directly to a sliding mass on a linear bearing. The electrical motor is controlled to slide the weight along the shafts in controlled steps. As a result, the photovoltaic panels are rotated automatically under the effect of controlled weight unbalance in fine angle increments to track solar trajectory without the need for traditional complex or costly mechanisms. Two light dependent resistors (LDR) sensors, mounted onto the surface of the solar photovoltaic panel, are exposed to solar irradiance and used to feed signals to a controller. A model of the solar tracking system is developed using ordinary differential equations, and numerically solved by MATLAB/Simulink™. The power consumption and tracking strategy of the proposed tracking system are estimated under realistic operating conditions (e.g. wind and brakes), and the power consumption is compared to the power generated by the photovoltaic panels. Optimum values for the sliding mass are suggested. Two photovoltaic modules are used to calculate the output parameters of the proposed tracking mechanism.

scholarly journals Removal of Basic Blue-41 dye from Water by Stabilized Magnetic Iron Nanoparticles on Clinoptilolite Zeolite

2020 ◽  
Vol 71 (2) ◽  
pp. 218-229 ◽  
Author(s):  
Shirin Afshin ◽  
Yousef Rashtbari ◽  
Mehdi Vosoughi ◽  
Rabia Rehman ◽  
Bahman Ramavandi ◽  
...  
Keyword(s):  
Reaction Time ◽  
Adsorption Process ◽  
Cost Effective ◽  
Operating Conditions ◽  
Process Efficiency ◽  
Freundlich Model ◽  
Initial Concentration ◽  
Wide Range ◽  
Pseudo Second Order ◽  
Nanocomposite Adsorbent

In this work, Zeolite/Fe3O4 nanocomposite used for adsorption of Blue 41 cationic dye from aqueous solutions in a wide range of concentrations. Analyzes of FTIR, XRD, FESEM, VSM and XRF have confirmed the nature and the structure of Zeolite/Fe3O4 nanocomposite adsorbent. The obtained results and analyzes determined that adsorption process efficiency increases by increasing reaction time, pH and amount of adsorbent and versus, increasing dye initial concentration causes significant decrease of adsorption efficiency. The obtained results of adsorption of isotherm and kinetics study illustrated that data follows Freundlich model and pseudo second order kinetics. Under optimum conditions of pH = 9, dye initial concentration of 100 mg/L, adsorbent dose of 3 g/L and reaction time of 60 min, removal efficiency was obtained 71.4 %. Totally results showed that Zeolite/Fe3O4 nanocomposite can be used by scrutiny of operating conditions of the adsorption process as a adsorbent with high effectiveness and availability, eco-friendly and cost-effective in order to removing dye from waste water of different industries.

scholarly journals Development of a New Low-Cost Tandem Variable Geometry Turbocharging Concept for Turbocharger Applications

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Rodrigo R. Erdmenger ◽  
Katya Menter ◽  
Rogier Giepman ◽  
Cathal Clancy ◽  
Aneesh Vadvadgi ◽  
...  
Keyword(s):  
High Reliability ◽  
Low Cost ◽  
Three Dimensional ◽  
Engine Performance ◽  
Cost Effective ◽  
Operating Conditions ◽  
Variable Geometry ◽  
Axial Turbine ◽  
Handling System ◽  
Manufacturing Techniques

The air handling system for large diesel/gas engines such as those used on locomotive, marine, and power generation applications require turbochargers with a high reliability and with turbomachinery capable to adjust to different operating conditions and transient requirements. The usage of variable geometry turbocharging (VGT) provides flexibility to the air handling system but adds complexity, cost and reduces the reliability of the turbocharger in exchange for improved engine performance and transient response. For this reason, it was desirable to explore designs that could provide the variability required by the air handling system, without the efficiency penalty of a conventional waste gate and with as little added complexity as possible. The current work describes a new low-cost variable geometry turbine design to address these requirements. The new tandem nozzle concept proposed is applicable to both axial and radial turbines and has been designed using conventional one-dimensional models and two- three-dimensional computational fluid dynamics (CFD) methods. The concept has furthermore been validated experimentally on two different test rigs. In order to avoid the long lead times of procuring castings, the nozzle for the axial turbine was manufactured using new additive manufacturing techniques. Both the axial turbine and the radial turbine designs showed that the concept is capable to achieve a mass flow variability of more than 15% and provide a robust and cost-effective alternative to conventional VGT designs by significantly reducing the number of moveable parts.

scholarly journals Development of a New Low-Cost Tandem VGT Concept for Turbocharger Applications

2018 ◽  
Author(s):  
Rodrigo R. Erdmenger ◽  
Katya Menter ◽  
Rogier Giepman ◽  
Cathal Clancy ◽  
Aneesh Vadvadgi ◽  
...  
Keyword(s):  
High Reliability ◽  
Low Cost ◽  
Engine Performance ◽  
Cost Effective ◽  
Operating Conditions ◽  
Variable Geometry ◽  
Axial Turbine ◽  
Handling System ◽  
Manufacturing Techniques ◽  
Complexity Cost

The air handling system for large diesel/gas engines such as those used on locomotive, marine, and power generation applications require turbochargers with a high reliability and with turbomachinery capable to adjust to different operating conditions and transient requirements. The usage of variable geometry turbocharging (VGT) provides flexibility to the air handling system but adds complexity, cost and reduces the reliability of the turbocharger in exchange for improved engine performance and transient response. For this reason, it was desirable to explore designs that could provide the variability required by the air handling system, without the efficiency penalty of a conventional waste gate and with as little added complexity as possible. The current work describes a new low-cost variable geometry turbine design to address these requirements. The new tandem nozzle concept proposed is applicable to both axial and radial turbines, and has been designed using conventional 1D models and 2D/3D CFD methods. The concept has furthermore been validated experimentally on two different test rigs. In order to avoid the long lead times of procuring castings, the nozzle for the axial turbine was manufactured using new additive manufacturing techniques. Both the axial turbine and the radial turbine designs showed that the concept is capable to achieve a mass flow variability of more than 15% and provide a robust and cost-effective alternative to conventional VGT designs by significantly reducing the number of moveable parts.

scholarly journals Constant-Current Gate Driver for GaN HEMTs Applied to Resonant Power Conversion

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2377
Author(s):  
Héctor Sarnago ◽  
Óscar Lucía ◽  
Iulian O. Popa ◽  
José M. Burdío
Keyword(s):  
High Performance ◽  
Cost Effective ◽  
Current Control ◽  
Operating Conditions ◽  
Constant Current ◽  
Efficient Operation ◽  
Zero Voltage Switching ◽  
Resonant Inverter ◽  
Wide Range ◽  
Gate Driver

New semiconductor technology is enabling the design of more reliable and high-performance power converters. In particular, wide bandgap (WBG) silicon carbide (SiC) and gallium nitride (GaN) technologies provide faster switching times, higher operating temperature, and higher blocking voltage. Recently, high-voltage GaN devices have opened the design window to new applications with high performance and cost-effective implementation. However, one of the main drawbacks is that these devices require accurate base current control to ensure safe and efficient operation. As a consequence, the base drive circuit becomes more complex and the final efficiency is decreased. This paper presents an improved gate driver circuit for GaN devices based on the use of a constant current regulator (CCR). The proposed circuit achieves constant current regardless of the operating conditions, solving variations with temperature, aging and operating conditions that may degrade the converter performance. Besides, the proposed circuit is reliable and cost-effective, being applicable to a wide range of commercial, industrial and automotive applications. In this paper, its application to a zero-voltage switching resonant inverter for domestic induction heating was performed to prove the feasibility of this concept.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

2D Color-Intensity Representation of Ultrasonic Thickness Gauge Measurements

2020 ◽  
pp. 1192-1198
Author(s):  
M.S. Mohammad ◽  
Tibebe Tesfaye ◽  
Kim Ki-Seong
Keyword(s):  
Cost Effective ◽  
The Other ◽  
Thickness Gauge ◽  
Color Intensity ◽  
Digital Readout ◽  
Flat Surfaces ◽  
Video Cameras ◽  
Wide Range ◽  
Cost Effective Alternative ◽  
Ultrasonic Thickness

Ultrasonic thickness gauges are easy to operate and reliable, and can be used to measure a wide range of thicknesses and inspect all engineering materials. Supplementing the simple ultrasonic thickness gauges that present results in either a digital readout or as an A-scan with systems that enable correlating the measured values to their positions on the inspected surface to produce a two-dimensional (2D) thickness representation can extend their benefits and provide a cost-effective alternative to expensive advanced C-scan machines. In previous work, the authors introduced a system for the positioning and mapping of the values measured by the ultrasonic thickness gauges and flaw detectors (Tesfaye et al. 2019). The system is an alternative to the systems that use mechanical scanners, encoders, and sophisticated UT machines. It used a camera to record the probe’s movement and a projected laser grid obtained by a laser pattern generator to locate the probe on the inspected surface. In this paper, a novel system is proposed to be applied to flat surfaces, in addition to overcoming the other limitations posed due to the use of the laser projection. The proposed system uses two video cameras, one to monitor the probe’s movement on the inspected surface and the other to capture the corresponding digital readout of the thickness gauge. The acquired images of the probe’s position and thickness gauge readout are processed to plot the measured data in a 2D color-coded map. The system is meant to be simpler and more effective than the previous development.

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