A General Formulation for Hydroforming of Arbitrarily-Shaped Boxes and Its Application to Hydroforming of an Elliptic-Circular Box

1998 ◽  
Vol 120 (3) ◽  
pp. 481-488 ◽  
Author(s):  
T. S. Noh ◽  
D. Y. Yang
Keyword(s):  
Velocity Field ◽  
Fluid Pressure ◽  
Frictional Coefficient ◽  
Total Power ◽  
Thickness Variation ◽  
Pressure Curve ◽  
Bound Solution ◽  
Total Power Consumption ◽  
Uniform Wall ◽  
Blank Size

A general kinematically admissible velocity field is suggested for the upper-bound solution of hydroforming of arbitrarily-shaped boxes. The suggested formulation is then applied to hydroforming of an elliptic-circular box. From the proposed velocity field, the fluid pressure vs. punch stroke relationship to render uniform thickness and the deformed configuration are determined by minimizing the total power consumption with respect to some chosen parameters. Experiments are carried out in the hydroforming press according to the computed pressure vs. punch stroke curve. The assumption of uniform wall thickness is confirmed by measuring the thickness variation. The effects of various process parameters including blank size, work-hardening exponent and frictional coefficient on the pressure curve are analyzed and discussed. It is thus shown that the proposed method of analysis in the present study can be effectively used for hydroforming of arbitrarily shaped boxes.

An Analysis of Three-Dimensional Upset Forging of Regular Polygonal Blocks by Using the Upper-Bound Method

1987 ◽  
Vol 109 (2) ◽  
pp. 155-160 ◽  
Author(s):  
D. Y. Yang ◽  
J. H. Kim
Keyword(s):  
Velocity Field ◽  
Upper Bound ◽  
Pure Copper ◽  
Three Dimensional ◽  
Total Power ◽  
Total Power Consumption ◽  
Upset Forging ◽  
Theoretical Predictions ◽  
Forging Load ◽  
Good Agreement

A simple kinematically admissible velocity field for three-dimensional deformation in upset forging of regular polygonal blocks is proposed which takes into account the sidewise spread as well as the bulging along thickness. From the proposed velocity field the upper-bound load and the deformed configuration are determined by minimizing the total power consumption with respect to three chosen parameters. Experiments are carried out with annealed commercially pure copper at room temperature for different thicknesses, billet shapes and lubrication conditions. The theoretical predictions both in the forging load and the deformed configuration are in good agreement with the experimental results. It is thus shown that the velocity field proposed in this work can be conveniently used for the prediction of the forging load and deformation in the upset forging of regular polygonal blocks.

scholarly journals An Economical and Precise Cooling Model and Its Application in a Single-Cylinder Diesel Engine

2021 ◽  
Vol 11 (15) ◽  
pp. 6749
Author(s):  
Zhifeng Xie ◽  
Ao Wang ◽  
Zhuoran Liu
Keyword(s):  
Diesel Engine ◽  
Cooling System ◽  
Combustion Engine ◽  
Electronic Control Unit ◽  
Total Power ◽  
Dynamical Characteristic ◽  
Water Jacket ◽  
Single Cylinder ◽  
Pump Speed ◽  
Total Power Consumption

The cooling system is an important subsystem of an internal combustion engine, which plays a vital role in the engine’s dynamical characteristic, the fuel economy, and emission output performance at each speed and load. This paper proposes an economical and precise model for an electric cooling system, including the modeling of engine heat rejection, water jacket temperature, and other parts of the cooling system. This model ensures that the engine operates precisely at the designated temperature and the total power consumption of the cooling system takes the minimum value at some power proportion of fan and pump. Speed maps for the cooling fan and pump at different speeds and loads of engine are predicted, which can be stored in the electronic control unit (ECU). This model was validated on a single-cylinder diesel engine, called the DK32. Furthermore, it was used to tune the temperature of the water jacket precisely. The results show that in the common use case, the electric cooling system can save the power of 255 W in contrast with the mechanical cooling system, which is about 1.9% of the engine’s power output. In addition, the validation results of the DK32 engine meet the non-road mobile machinery China-IV emission standards.

scholarly journals On-CMOS Image Sensor Processing for Lane Detection

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3713
Author(s):  
Soyeon Lee ◽  
Bohyeok Jeong ◽  
Keunyeol Park ◽  
Minkyu Song ◽  
Soo Youn Kim
Keyword(s):  
Edge Detection ◽  
High Speed ◽  
Cmos Image Sensor ◽  
Image Sensor ◽  
Image Resolution ◽  
Lane Detection ◽  
Frame Rate ◽  
Total Power ◽  
Detection Accuracy ◽  
Total Power Consumption

This paper presents a CMOS image sensor (CIS) with built-in lane detection computing circuits for automotive applications. We propose on-CIS processing with an edge detection mask used in the readout circuit of the conventional CIS structure for high-speed lane detection. Furthermore, the edge detection mask can detect the edges of slanting lanes to improve accuracy. A prototype of the proposed CIS was fabricated using a 110 nm CIS process. It has an image resolution of 160 (H) × 120 (V) and a frame rate of 113, and it occupies an area of 5900 μm × 5240 μm. A comparison of its lane detection accuracy with that of existing edge detection algorithms shows that it achieves an acceptable accuracy. Moreover, the total power consumption of the proposed CIS is 9.7 mW at pixel, analog, and digital supply voltages of 3.3, 3.3, and 1.5 V, respectively.

scholarly journals Efficient Operation Method of Aquifer Thermal Energy Storage System Using Demand Response

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3129
Author(s):  
Jewon Oh ◽  
Daisuke Sumiyoshi ◽  
Masatoshi Nishioka ◽  
Hyunbae Kim
Keyword(s):  
Energy Storage ◽  
Power Consumption ◽  
Thermal Energy ◽  
Demand Response ◽  
Thermal Energy Storage ◽  
Heat Storage ◽  
Storage System ◽  
Total Power ◽  
Operation Method ◽  
Total Power Consumption

The mass introduction of renewable energy is essential to reduce carbon dioxide emissions. We examined an operation method that combines the surplus energy of photovoltaic power generation using demand response (DR), which recognizes the balance between power supply and demand, with an aquifer heat storage system. In the case that predicts the occurrence of DR and performs DR storage and heat dissipation operation, the result was an operation that can suppress daytime power consumption without increasing total power consumption. Case 1-2, which performs nighttime heat storage operation for about 6 h, has become an operation that suppresses daytime power consumption by more than 60%. Furthermore, the increase in total power consumption was suppressed by combining DR heat storage operation. The long night heat storage operation did not use up the heat storage amount. Therefore, it is recommended to the heat storage operation at night as much as possible before DR occurs. In the target area of this study, the underground temperature was 19.1 °C, the room temperature during cooling was about 25 °C and groundwater could be used as the heat source. The aquifer thermal energy storage (ATES) system in this study uses three wells, and consists of a well that pumps groundwater, a heat storage well that stores heat and a well that used heat and then returns it. Care must be taken using such an operation method depending on the layer configuration.

Design and Layout of a High-Performance PWM Control Class D Amplifiers IC Systems

2012 ◽  
Vol 203 ◽  
pp. 469-473
Author(s):  
Ruei Chang Chen ◽  
Shih Fong Lee
Keyword(s):  
Low Power ◽  
High Performance ◽  
Low Voltage ◽  
Design Flow ◽  
Total Power ◽  
Cmos Process ◽  
Low Power Circuits ◽  
Class D ◽  
Total Power Consumption ◽  
Power Circuits

This paper presents the design and implementation of a novel pulse width modulation control class D amplifiers chip. With high-performance, low-voltage, low-power and small area, these circuits are employed in portable electronic systems, such as the low-power circuits, wireless communication and high-frequency circuit systems. This class D chip followed the chip implementation center advanced design flow, and then was fabricated using Taiwan Semiconductor Manufacture Company 0.35-μm 2P4M mixed-signal CMOS process. The chip supply voltage is 3.3 V which can operate at a maximum frequency of 100 MHz. The total power consumption is 2.8307 mW, and the chip area size is 1.1497×1.1497 mm2. Finally, the class D chip was tested and the experimental results are discussed. From the excellent performance of the chip verified that it can be applied to audio amplifiers, low-power circuits, etc.

Low-Carbon Clean Technology for Waste Energy Recovery in Power Plants Based on Green Environmental Protection

2021 ◽  
Author(s):  
Yong Tian ◽  
Wen-Jing Liu ◽  
Qi-jie Jiang ◽  
Xin-Ying Xu
Keyword(s):  
Power Generation ◽  
Power Plants ◽  
Biomass Energy ◽  
Energy Utilization ◽  
Pollutant Emissions ◽  
Total Power ◽  
Economic Losses ◽  
Biomass Waste ◽  
Emission Analysis ◽  
Total Power Consumption

With the development of biomass power generation technology, biomass waste has a more excellent recycling value. The article establishes a biomass waste inventory model based on the material flow analysis method and predicts raw material waste’s energy utilization potential. The results show that the amount of biomass waste generated from 2016 to 2020 is on the rise. In 2020, biomass waste’s energy utilization can reach 107,802,300 tons, equivalent to 1,955.28PJ of energy. Through biomass energy analysis and emission analysis, the results show that the biomass waste can generate 182.02 billion kW⋅h in 2020, which can replace 35.9% of the region’s total power consumption, which is compared with the traditional power generation method under the same power generation capacity. Power generation can reduce SO2 emissions by 250,400 tons, NOx emissions by 399,300 tons, and PM10 emissions by 49,700 tons. Reduce direct economic losses by 712 million yuan. Therefore, Chinese promotion of the recycling of biomass waste and the acceleration of the biomass energy industry’s development is of great significance for reducing pollutant emissions and alleviating energy pressure.

scholarly journals A Novel Differential Log-Companding Amplifier for Biosignal Sensing

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Zigang Dong ◽  
Xiaolin Zhou ◽  
Yuanting Zhang
Keyword(s):  
Power Consumption ◽  
Supply Voltage ◽  
Nonlinear Function ◽  
New Method ◽  
Total Power ◽  
Maximum Output ◽  
Output Current ◽  
Current Range ◽  
Symmetrical Configuration ◽  
Total Power Consumption

We proposed a new method for designing the CMOS differential log-companding amplifier which achieves significant improvements in linearity, common-mode rejection ratio (CMRR), and output range. With the new nonlinear function used in the log-companding technology, this proposed amplifier has a very small total harmonic distortion (THD) and simultaneously a wide output current range. Furthermore, a differential structure with conventionally symmetrical configuration has been adopted in this novel method in order to obtain a high CMRR. Because all transistors in this amplifier operate in the weak inversion, the supply voltage and the total power consumption are significantly reduced. The novel log-companding amplifier was designed using a 0.18 μm CMOS technology. Improvements in THD, output current range, noise, and CMRR are verified using simulation data. The proposed amplifier operates from a 0.8 V supply voltage, shows a 6.3 μA maximum output current range, and has a 6 μW power consumption. The THD is less than 0.03%, the CMRR of this circuit is 74 dB, and the input referred current noise density is166.1 fA/Hz. This new method is suitable for biomedical applications such as electrocardiogram (ECG) signal acquisition.

Some pressure and fluid dynamic characteristics of the canine epidural space

1977 ◽  
Vol 232 (3) ◽  
pp. H255-H259
Author(s):  
R. G. Bengis ◽  
A. C. Guyton
Keyword(s):  
Epidural Space ◽  
Fluid Dynamic ◽  
Fluid Pressure ◽  
Simultaneous Recording ◽  
Positive Pressure ◽  
Pressure Curve ◽  
Epidural Pressure ◽  
Volume Depletion ◽  
Significant Drop ◽  
Epidural Catheters

Pressure measured in teh epidural space of 50 dogs was consistently negative (subatmospheric). Acutely implanted epidural catheters gave an average reading of -2.72 mmHg (n = 44, SE = 0.18), whereas chronically implanted catheters gave more negative readings, averaging -5.8 mmHg (n = 6, SE = 0.49). Since the chronically implanted catheters permit healing, resolution of hemorrhage, and resealing of the epidural space to take place, resulting in equilibration of microcirulatory forces, these readings are believed to represent more closely the true epidural pressure. Also these results approximate closely the calculated and measured interstitial fluid pressures obtained by different techniques in other loose areolar connective tissue systems. Compliance studies, using a double-lumen catheter for simultaneous recording and infusing in the epidural space, showed increasing compliance as the pressure rose into the positive pressure range, with an eventual plateau of the volume-pressure curve at the level of the concomitantly measured cerebrospinal fluid pressure (avg = +5.73 mmHg, n = 10, SE = 0.48). Intravenous volume loading using Tyrode solution caused a large rise in epidural pressure, and volume depletion with diuretics caused a significant drop in epidural pressure.

Exergy Analysis of a Novel Cryogenic Concept for the Liquefaction of Natural Gas Integrated Into an Air Separation Process

2016 ◽  
Author(s):  
S. Tesch ◽  
T. Morosuk ◽  
G. Tsatsaronis
Keyword(s):  
Natural Gas ◽  
Power Consumption ◽  
Exergy Analysis ◽  
Primary Energy ◽  
Separation Process ◽  
Air Separation ◽  
Total Power ◽  
Separation Unit ◽  
Total Power Consumption ◽  
Liquefaction Temperature

The increasing demand for primary energy leads to a growing market of natural gas and the associated market for liquefied natural gas (LNG) increases, too. The liquefaction of natural gas is an energy- and cost-intensive process. After exploration, natural gas, is pretreated and cooled to the liquefaction temperature of around −160°C. In this paper, a novel concept for the integration of the liquefaction of natural gas into an air separation process is introduced. The system is evaluated from the energetic and exergetic points of view. Additionally, an advanced exergy analysis is conducted. The analysis of the concepts shows the effect of important parameters regarding the maximum amount of liquefiable of natural gas and the total power consumption. Comparing the different cases, the amount of LNG production could be increased by two thirds, while the power consumption is doubled. The results of the exergy analysis show, that the introduction of the liquefaction of natural gas has a positive effect on the exergetic efficiency of a convetional air separation unit, which increases from 38% to 49%.

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