Michael Petrucci, Amir Faghri^*

Frontiers in Heat and Mass Transfer, Vol.11, pp. 1-9, 2018, DOI:10.5098/hmt.11.37

Abstract The results of integrating heat pipes into the vanes of a turbofan engine are presented. These Heat Pipe Turbine Vanes (HPTV) are integrated into the compressor exit, turbine inlet, and exhaust flow for vane cooling and waste heat recovery. Thermodynamic analysis of HPTV turbofan engines is done and comparisons are made between heat pipe turbine vane cooling and conventional film cooling techniques. Heat transfer through the vanes is analyzed using a thermal network model. Limitations on the heat transfer caused by various limiting phenomena within the heat pipe are also determined. More >

Fengxia Shi^1,2, Yucai Tang^1,*, Dedong Ma¹, Xiangyun Shi¹, Guangbiao Zhao¹

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2481-2497, 2023, DOI:10.32604/fdmp.2023.028416

Abstract In order to analyze the response of a hydraulic turbine to a variation in the operating conditions, different laws of variation in time of the mass flow rate have been considered. After validating the overall numerical framework through comparison with relevant experiments, the performances of the considered turbine have been analyzed from a fluid-dynamic point of view. The results show that different time profiles of the mass flow rate (in this work, for simplicity, referred to as “transition functions”) have a varying influence on the transient behavior of the turbine. When a quadratic function is considered for the case of… More > Graphic Abstract

Chunyan Zhang¹, Shuaishuai Wang^1,2, Yinhu Qiao^1,*, Zhiqiang Zhang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2661-2679, 2023, DOI:10.32604/fdmp.2023.028059

Abstract Numerical simulations are conducted to improve the energy acquisition efficiency of H-type vertical axis wind turbines through the optimization of the related blade airfoil aerodynamic performance. The Bézier curve is initially used to fit the curve profile of a NACA2412 airfoil, and the moving asymptote algorithm is then exploited to optimize the design of the considered H-type vertical-axis wind-turbine blade airfoil for a certain attack angle. The results show that the maximum lift coefficient of the optimized airfoil is 8.33% higher than that of the original airfoil. The maximum lift-to-drag ratio of the optimized airfoil exceeds the maximum lift-to-drag ratio… More > Graphic Abstract

Nian Wang, Mingjie Zhang, Sulaiman Alsaleem, Lesley M. Wright, Je-Chin Han^*

Frontiers in Heat and Mass Transfer, Vol.13, pp. 1-13, 2019, DOI:10.5098/hmt.13.9

Abstract This study investigates turbine blade, leading edge cooling from normal or tangential impinging jets. These jets impinging on a semi-cylindrical, inner surface are constrained to discharge in a single direction. The downstream jets are affected by the crossflow originating from the upstream jets. To understand the thermal flow physics, numerical simulations are performed using the realizable k- turbulence model. Both the experimental and numerical results show crossflow is more detrimental to normal impinging jets than the tangential jets. Furthermore, with a significant temperature drop across the jet plate, designers must correctly interpret jet impingement results. More >

Oussama Accouche^1,*, Rajan Kumar Gangadhari²

CMC-Computers, Materials & Continua, Vol.76, No.1, pp. 151-173, 2023, DOI:10.32604/cmc.2023.038648

Abstract Distributed renewable energy sources offer significant alternatives for Qatar and the Arab Gulf region’s future fuel supply and demand. Microgrids are essential for providing dependable power in difficult-to-reach areas while incorporating significant amounts of renewable energy sources. In energy-efficient data centers, distributed generation can be used to meet the facility’s overall power needs. This study primarily focuses on the best energy management practices for a smart microgrid in Qatar while taking demand-side load management into account. This article looked into a university microgrid in Qatar that primarily aimed to get all of its energy from the grid. While diesel generators… More >

Caifeng Wen^1,2, Qiang Wang^1,*, Yang Cao¹, Liru Zhang^1,2, Wenxin Wang³, Boxin Zhang¹, Qian Du¹

Energy Engineering, Vol.120, No.7, pp. 1603-1619, 2023, DOI:10.32604/ee.2023.027074

Abstract To solve the problems of large losses and low productivity of permanent magnet synchronous generators used in wind power systems, the field-circuit coupling method is used to accurately solve the electromagnetic field and temperature field of the generator. The loss distribution of the motor is accurately obtained by considering the influence of external circuit characteristics on its internal physical field. By mapping the losses to the corresponding part of the three-dimensional finite element model of the motor, the temperature field is solved, and the global temperature distribution of the generator, considering the influence of end windings, is obtained. By changing… More >

O. M. Oyewola^a,b,*, O. S. Ismail^b, J. O. Bosomo^b

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-5, 2021, DOI:10.5098/hmt.17.8

Abstract This paper investigates possible inherent modifications of the radiative heat source term due to the influence of turbulence in the thermal radiation field of a gas turbine combustor flame. Adapting a flame temperature of 2000[K], COMSOL Multiphysics software was utilized to numerically simulate the process, assuming a gray gas participating medium with absorption coefficient of 0.03[m^-1]. The analysis of the results for five (5) different radial cut sections of the simulated combustor chamber shows that turbulence-radiation interactions cause radiative heat losses from the flame, with the divergence of the radiative heat flux having a deviation factor of 3.48, and a… More >

Xiao Sun^a, Fan-Kang Zeng^a, Jia-Bing Yang^a, Feng-Lin Zhou^a, Yu-Liang Zhang^b,*

Frontiers in Heat and Mass Transfer, Vol.17, pp. 1-6, 2021, DOI:10.5098/hmt.17.5

Abstract In order to better study the internal flow characteristics of centrifugal pump as turbine, CFX software is employed to carry out numerical simulation to obtain flow field under different working conditions for pump as turbine based on the standard k - epsilon turbulence model and the SIMPLEC algorithm. The efficiency curves of the pump and pump as turbine are obtained under different working conditions. The results show that the effciency characteristics of the pump change greatly during the process of pumping. The efficiency of the turbine is higher than that of the pump under the respective optimal operating conditions. The… More >

Yuhan Liu, Yuqiao Zheng^*, Zhuang Ma, Cang Wu

Energy Engineering, Vol.120, No.5, pp. 1223-1237, 2023, DOI:10.32604/ee.2023.026329

Abstract An operating condition recognition approach of wind turbine spindle is proposed based on supervisory control and data acquisition (SCADA) normal data drive. Firstly, the SCADA raw data of wind turbine under full working conditions are cleaned and feature extracted. Then the spindle speed is employed as the output parameter, and the single and combined normal behavior model of the wind turbine spindle is constructed sequentially with the pre-processed data, with the evaluation indexes selected as the optimal model. Finally, calculating the spindle operation status index according to the sliding window principle, ascertaining the threshold value for identifying the abnormal spindle… More >

Jin Wang¹, Zhen Liu^1,*, Ying Wang¹, Caifeng Wen^2,3, Jianwen Wang^2,3

Energy Engineering, Vol.120, No.5, pp. 1149-1162, 2023, DOI:10.32604/ee.2023.025209

Abstract Analyzing the strain signal of wind turbine blade is the key to studying the load of wind turbine blade, so as to ensure the safe and stable operation of wind turbine in natural environment. The strain signal of the wind turbine blade under continuous crosswind state has typical non-stationary and unsteady characteristics. The strain signal contains a lot of noise, which makes the analysis error. Therefore, it is very important to denoise and extract features of measured signals before signal analysis. In this paper, the joint algorithm of ensemble empirical mode decomposition (EEMD) and wavelet transform (WT) is used for… More >