The Experts below are selected from a list of 16416 Experts worldwide ranked by ideXlab platform
Guoqing Zhang - One of the best experts on this subject based on the ideXlab platform.
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effects of eco friendly Cooling Strategy on machining performance in micro scale diamond turning of ti 6al 4v
Journal of Cleaner Production, 2020Co-Authors: Peng Huang, Guoqing Zhang, Wule Zhu, Haitao Wang, Zhiwei ZhuAbstract:Abstract Titanium alloys are difficult-to-cut materials due to their low elastic modulus and poor thermal conductivity. To deepen the understanding of the cutting performance for Ti–6Al–4V under various eco-friendly Cooling conditions, surface integrity, cutting forces, and tool wear were comprehensively investigated through cutting experiments implementing three Cooling methods, namely, cryogenic gas (CG), minimum quantity lubrication (MQL), and a combination of CG and MQL (CG + MQL), respectively. The results show that the lowest surface roughness ( S a = 76.71 nm) was achieved at a low spindle speed under the CG + MQL Cooling conditions. This suggests that of the three Cooling methods, the CG + MQL hybrid Cooling method achieved the highest Cooling efficiency. Compared with the MQL Cooling method, the CG + MQL Cooling method led to more pronounced tool wear and material adhesion due to reduced oil-based lubricity caused by low temperatures. Under the MQL Cooling conditions, the elastic recovery of Ti–6Al–4V accelerated the formation of micro-cleavages on the clearance face of the diamond tool. Additionally, the depth of cut was also comparable to the tool edge radius in the micro-scale diamond turning. Compared with the conventional turning of Ti–6Al–4V, this round-edge effect, combined with the adhesion and built-up edge, led to a relatively stronger friction effect, evidenced by an increase in the coefficient of friction from 1.027 to 3.532, and higher specific cutting energy under all the Cooling conditions in micro-scale diamond turning.
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Experimental investigation on a novel liquid-Cooling Strategy by coupling with graphene-modified silica gel for the thermal management of cylindrical battery
Applied Thermal Engineering, 2019Co-Authors: Dequan Zhou, Xiao-qing Yang, Xiangyun Liu, Guoqing ZhangAbstract:Abstract As the most widely used battery thermal management (BTM) technology in pure/hybrid electric vehicles, liquid Cooling is facing challenge of enhancing the heat transfer capability between the Cooling tubes and the curved surface of cylindrical cells. In this work, a kind of graphene oxide (GO) -modified silica gel (GO-SG) is prepared and simply filled in the space between the cylindrical cells and water Cooling tubes. The addition of GO endows the GO-SG with enhanced thermal conductivity to transfer the generated heat to the tubes effectively, thus giving rise to a superior Cooling and temperature-uniformed performance of the battery module. For instance, during the fast charging process of 2 and 3C, the maximum temperature (Tmax) of the water Cooling module with GO-SG is as low as 37.7 and 42.0 °C, and the corresponding temperature difference (ΔT) is controlled below 4 and 5 °C, respectively. During the cycling tests, the Tmax and ΔT can be maintained below 40 and 4 °C, respectively. We believe that this approach may open new thoughts for the structural optimization of the liquid Cooling technology and thus promote the development of the BTM systems.
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experimental examination of large capacity lifepo4 battery pack at high temperature and rapid discharge using novel liquid Cooling Strategy
International Journal of Energy Research, 2018Co-Authors: Cong Wang, Guoqing Zhang, Jin Huang, Ziyuan Wang, Like Meng, Wenfu Situ, Mumin RaoAbstract:Summary To overcome the significant amounts of heat generated by large-capacity battery modules under high-temperature and rapid-discharge conditions, a new liquid Cooling Strategy based on thermal silica plates was designed and developed. The superior thermal conductivity of the thermal silica plate combined with the excellent Cooling effect of water led to a feasible and effective composite liquid Cooling system during long cycle testing. The experimental results showed that the addition of thermal silica plates can greatly improve the Cooling capacity that can allow the maximum temperature difference to be controlled at 6.1°C and reduce the maximum temperature of the battery module by 11.3°C, but still outside the optimum operating temperature range. The water flow significantly enhanced the Cooling performance/stability, and slight temperature fluctuations were observed during cycling. The Cooling performance obviously improved as the flow rate rose. When the velocity reached a critical value, further increase in water flow rate induced a slight influence on the Cooling capacity due to the limitation of the materials. The maximum temperature (Tmax) could be reduced to 48.7°C, and temperature difference (∆T) could be maintained within 5°C when the water flow velocity increased to 4 mL/s, which was determined as the best value. The energy consumed by the water pump is only 1.37% of the total energy of the battery module. Overall, these findings should provide novel strategies for the design and optimization of battery thermal management system.
Zhiwei Zhu - One of the best experts on this subject based on the ideXlab platform.
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effects of eco friendly Cooling Strategy on machining performance in micro scale diamond turning of ti 6al 4v
Journal of Cleaner Production, 2020Co-Authors: Peng Huang, Guoqing Zhang, Wule Zhu, Haitao Wang, Zhiwei ZhuAbstract:Abstract Titanium alloys are difficult-to-cut materials due to their low elastic modulus and poor thermal conductivity. To deepen the understanding of the cutting performance for Ti–6Al–4V under various eco-friendly Cooling conditions, surface integrity, cutting forces, and tool wear were comprehensively investigated through cutting experiments implementing three Cooling methods, namely, cryogenic gas (CG), minimum quantity lubrication (MQL), and a combination of CG and MQL (CG + MQL), respectively. The results show that the lowest surface roughness ( S a = 76.71 nm) was achieved at a low spindle speed under the CG + MQL Cooling conditions. This suggests that of the three Cooling methods, the CG + MQL hybrid Cooling method achieved the highest Cooling efficiency. Compared with the MQL Cooling method, the CG + MQL Cooling method led to more pronounced tool wear and material adhesion due to reduced oil-based lubricity caused by low temperatures. Under the MQL Cooling conditions, the elastic recovery of Ti–6Al–4V accelerated the formation of micro-cleavages on the clearance face of the diamond tool. Additionally, the depth of cut was also comparable to the tool edge radius in the micro-scale diamond turning. Compared with the conventional turning of Ti–6Al–4V, this round-edge effect, combined with the adhesion and built-up edge, led to a relatively stronger friction effect, evidenced by an increase in the coefficient of friction from 1.027 to 3.532, and higher specific cutting energy under all the Cooling conditions in micro-scale diamond turning.
Abdulhakim Ali Sultan - One of the best experts on this subject based on the ideXlab platform.
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effects of geometric parameters of wavy edge bull nose helical end mill on cutting force prediction in end milling of inconel 718 under mql Cooling Strategy
Journal of Manufacturing Processes, 2016Co-Authors: Abdulhakim Ali Sultan, Chukwujekwu A OkaforAbstract:Abstract This paper presents the results of the development of a mechanistic cutting force prediction model for wavy-edge, bull-nose, helical endmill (WEBNHE), which was validated and used to investigate the effects of the geometric parameters of the WEBNHE on the predicted cutting force components and the resultant cutting force. The mechanistic cutting force prediction model was validated by conducting end-milling experiments on Inconel 718 and incorporating the effect of the Minimum Quantity Lubrication (MQL) Cooling Strategy through experimentally identified six cutting force and edge force coefficients. The geometric parameters investigated in this research were: the wavelength, wave magnitude, axial shift of the linear part, and the helix angle of the wavy cutting edges. These parameters were varied one at a time, and the cutting force components for each variation were predicted using the mechanistic cutting force prediction model. The results show that the predicted and measured cutting force components were in good agreement in magnitude and shape. The cutting force components generated from the end-milling under the MQL Cooling Strategy were lower than under the emulsion Cooling Strategy. The magnitudes and shapes of the predicted cutting force components and the resultant cutting force of the WEBNHE were unique (asymmetric) in magnitude and shape compared to those of standard, bull-nose, helical endmill (SBNHE) due to the uniqueness of the wavy-cutting edge geometry. The results also show that the predicted cutting force component in the feed direction Fy is the largest and the most affected by the geometric parameters, followed by Fx. However, Fz is insignificantly affected. It was also observed that the maximum magnitudes and ranges of the cutting force component in the feed direction Fy and the resultant cutting force FR increased with an increase in the wave magnitude and decrease with increase of the wavelength, axial shift, and the helix angle. The wavy cutting edge spends more time in the cutting zone than the standard, helical, cutting edge; this extra time affects the frequency content of the cutting force signals generated by the endmill and improves the end-milling dynamics. Additionally, the distribution of the cutting forces on the wavy cutting edges was not equal due to the asymmetric cutting edge geometry.
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Development of a mechanistic cutting force model for wavy-edge bull-nose helical end-milling of inconel 718 under emulsion Cooling Strategy
Applied Mathematical Modelling, 2016Co-Authors: A. Chukwujekwu Okafor, Abdulhakim Ali SultanAbstract:This paper presents the results of the development of a mechanistic cutting force model to predict cutting forces in high-speed end-milling of Inconel 718 using a wavy-edge, bull-nose, helical endmill (which hereafter will be abbreviated as WEBNHE). The model incorporates the effects of emulsion Cooling Strategy into the mechanistic cutting force model through the experimental determination of six specific cutting force and edge force coefficients. The cutting force is predicted as three components (Fx, Fy, and Fz) and the resultant cutting force FR. The mechanistic cutting force model depends on a mathematical model to represent the geometry of this endmill, which is also developed in this research. The mechanistic model also depends on three cutting force coefficients in the tangential, radial, and axial directions (ktc, krc, kac, respectively), and on three edge force coefficients (kte, kre, kae), also in the tangential, radial, and axial directions. These coefficients are determined experimentally in a separate work in which "emulsion" was applied as the Cooling Strategy. MATLAB codes were developed and used to simulate the developed mathematical and mechanistic cutting force models. Finally, to validate the mechanistic cutting force model, machining experiments were conducted and real cutting force components were measured and compared with the predicted cutting force components. The predicted values agree fairly well with the experimentally measured values in both magnitude and shape. The percentage of the prediction error for the highest peak force magnitudes at 93 rpm were 11.38%, -0.46%, and 11% for the Fx, Fy, and Fzcomponents respectively, while the percentage prediction error for the lowest cutting force magnitudes are 15.25%, 17.84%, and 10% for Fx, Fy, and Fzcomponents respectively. The developed mechanistic cutting force model can be used to investigate the effect of tool geometry and machining parameters on cutting forces, machining power, machine tool vibration, and to simulate the end-milling process to improve machinability and productivity, and also to understand more fully the end-milling process using WEBNHE.
Rami Zeinelabdei - One of the best experts on this subject based on the ideXlab platform.
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critical review of latent heat storage systems for free Cooling in buildings
Renewable & Sustainable Energy Reviews, 2018Co-Authors: Rami Zeinelabdei, Siddig OmeAbstract:Buildings have a major contribution to the global energy consumption. Heating, ventilating and air conditioning systems (HVAC) are responsible for most of the energy use in buildings. Thus, clean and sustainable alternatives such as free Cooling of buildings have recently gained much attention as means to reduce the operation hours and capacity of the conventional Cooling and heating systems. The free Cooling could be provided by collecting the natural cold energy during night time in appropriate thermal storage form and this could be retrieved when needed. Phase change materials are exploited by a number of investigators as a storage medium in free Cooling applications, as these substances possess high energy densities, and absorb and release heat at a narrow temperature range, hence, the comfort temperature can be maintained day and night. The objectives of this article are to provide a comprehensive review on recent development on free Cooling technologies incorporating latent heat storage and to shit lights on the most significant parameters affecting the performance of these materials in free Cooling Strategy. The outcomes of this review would be helpful in providing clear insight information on potential improvements that can be applied to the storage materials. All the reviewed studies demonstrated that the night Cooling Strategy using PCMs has the capacity to maintain the indoor temperature well within the comfort zone whilst providing a considerable reduction in Cooling loads in all considered climates.
Ramin Karami - One of the best experts on this subject based on the ideXlab platform.
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acquiring the best Cooling Strategy based on thermal comfort and 3e analyses for small scale residential buildings at diverse climatic conditions
International Journal of Refrigeration-revue Internationale Du Froid, 2015Co-Authors: Hamidreza Hasani Balyani, Ali Sohani, Hoseyn Sayyaadi, Ramin KaramiAbstract:Abstract A methodology for selecting the best Cooling system for small scale residential building was introduced. A benchmark building was assumed to be cooled by various Cooling alternatives. The proposed systems were analyzed based on 3E (energy, economic, and environmental) as well as thermal comfort analyses. Finally, based on fuzzy-AHP method, the best Cooling alternative in each climatic condition was selected. It was suggested to implement direct evaporative Cooling (DEC) in all dry areas. In wet and hot areas, the best option was the vapor compression system; however, in temperate and humid, very hot and semi-humid, and temperate and wet cities, desiccant-enhanced evaporative Cooling (DEVap) was the best alternative. It reduced the annual primary energy consumption (PEC) and carbon dioxide emission (CDE) up to 13970 kWh and 3.3 tons of CO2, respectively. Implementing DEC reduced PEC, CDE, and Cooling cost of dry area up to 4875 kWh, 5.6 tons of CO2, and 168 $, respectively.