Hussein Al-Gburi^*, Akeel Abbas Mohammed, Audai Hussein Al-Abbas

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-7, 2023, DOI:10.5098/hmt.20.17

Abstract Transferring thermal energy efficiently necessitates utilizing a heat exchanger capable of producing the full thermal power of the energy supply at lowest possible cost and time. Therefore, in the present investigation, the impact of corrugated helical coil concentric tube-in-tube heat exchanger on the thermal performance is investigated experimentally. As a continuous in our issue of heat exchanger, the corrugated helical tube-in-tube is carried out and compared with smooth helical tube-in-tube for free convection heat transfer. The set-up of the experimental apparatus are designed and utilized to be appropriate for the cooling and heating systems of working fluid. The impacts of… More >

Zubing Tang^*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2161-2170, 2023, DOI:10.32604/fdmp.2023.026608

Abstract The mechanical behavior of the test string in deep wells is generally relatively complex as a result of the high temperature and high pressure, severe dogleg and buckling effects, which in some circumstances can even lead to string failure. Traditional computational methods for the analysis of these behaviors are often inaccurate. For this reason, here a more accurate mechanical model of the test string is introduced by considering variables such as temperature, pressure, wellbore trajectory, and buckling, as well as combining them with the deformation and string constraint conditions brought in by changes in temperature and pressure during the tripping,… More >

Ruidong Wu¹, Guowei Wang^2,3,4,*, Zhixing Yang¹, Ruiquan Liao^2,3,4, Yang Cheng^2,3,4

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2053-2066, 2023, DOI:10.32604/fdmp.2023.026301

Abstract An experimental analysis has been conducted to study the process of fluid accumulation for different borehole trajectories. More specifically, five heel angles have been experimentally realized to simulate the borehole trajectory of the sloping section of the formation. The fluid-carrying capacity, pressure drop and fluid discharge volatility have been investigated for these conditions and, accordingly, the relationship between heel angle and wellbore pressure drop fluid-carrying capacity has been determined. The results show that while the reasonable roll angle can increase the pressure loss in the wellbore, it is beneficial to drainage. In terms of pressure loss and liquid-carrying capacity, when… More > Graphic Abstract

Shu-Yin Chiang^*, Dong-Ye Wu

CMC-Computers, Materials & Continua, Vol.75, No.2, pp. 2509-2526, 2023, DOI:10.32604/cmc.2023.036466

Abstract Physiological signals indicate a person’s physical and mental state at any given time. Accordingly, many studies extract physiological signals from the human body with non-contact methods, and most of them require facial feature points. However, under COVID-19, wearing a mask has become a must in many places, so how non-contact physiological information measurements can still be performed correctly even when a mask covers the facial information has become a focus of research. In this study, RGB and thermal infrared cameras were used to execute non-contact physiological information measurement systems for heart rate, blood pressure, respiratory rate, and forehead temperature for… More >

Jikang Xu^1,4, Ruichuan Li^1,2,*, Yi Cheng², Yanchao Li³, Junru Yang³, Chenyu Feng⁴, Xinkai Ding², Huazhong Zhang⁵

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.7, pp. 1817-1836, 2023, DOI:10.32604/fdmp.2023.022602

Abstract Electro-hydraulic proportional valve is the core control valve in many hydraulic systems used in agricultural and engineering machinery. To address the problem related to the large throttling losses and poor stability typically associated with these valves, here, the beneficial effects of a triangular groove structure on the related hydraulic response are studied. A mathematical model of the pressure compensation system based on the power-bond graph method is introduced, and the AMESim software is used to simulate its response. The results show that the triangular groove structure increases the jet angle and effectively compensates for the hydrodynamic force. The steady-state differential… More > Graphic Abstract

Chao Zhu¹, Zhuopei Liu², Hao Chen^2,3, Yangyang Li^2,3,*

Energy Engineering, Vol.120, No.5, pp. 1081-1105, 2023, DOI:10.32604/ee.2023.026000

Abstract Experiments were conducted on a diesel-methanol dual-fuel (DMDF) engine modified by a six-cylinder, turbo-charged, inter-cooled diesel engine. According to the number of diesel injection, the experiments are divided to two parts: the single injection mode and double injection mode. The results show that, at the double injection mode, the maximum of pressure rise rate is small and the engine runs smoothly, however, knock still occurs when the co-combustion ratio (CCR) is big enough. Under knock status, the power density of the block vibration concentrating at some special frequencies rises dramatically, and the special frequency of single injection mode (about 4.1… More >

Guodong Zeng¹, Chao Li^1,*, Yang Fang¹, Hongming Huang^1,2, Hao Li^1,3, Yishen Xu¹

Journal of Renewable Materials, Vol.11, No.5, pp. 2453-2467, 2023, DOI:10.32604/jrm.2023.025871

Abstract For evaluating the water stability of hot-mixed renewable asphalt mixture (HRM), the traditional methods are all tested under still water conditions. Except for damage in still water conditions, the hydrodynamic pore pressure generated by the tire driving on the surface water has a great impact. Thus, the RAP contents of the HRMs were designed at 0%, 30%, 45% and 60% with AC-25 gradation. Then, the self-designed evaluation methods of water stability and dynamic modulus were studied. Finally, the mechanism of the influence of hydrodynamic pore pressure damage on HRMs was studied. The results show that the water stability of HRM… More >

Hoon Ko¹, Chul Park², Wu Seong Kang³, Yunyoung Nam⁴, Dukyong Yoon⁵, Jinseok Lee^1,*

Computer Systems Science and Engineering, Vol.46, No.2, pp. 2369-2381, 2023, DOI:10.32604/csse.2023.035641

Abstract Adequate oxygen in red blood cells carrying through the body to the heart and brain is important to maintain life. For those patients requiring blood, blood transfusion is a common procedure in which donated blood or blood components are given through an intravenous line. However, detecting the need for blood transfusion is time-consuming and sometimes not easily diagnosed, such as internal bleeding. This study considered physiological signals such as electrocardiogram (ECG), photoplethysmogram (PPG), blood pressure, oxygen saturation (SpO2), and respiration, and proposed the machine learning model to detect the need for blood transfusion accurately. For the model, this study extracted… More >

Renjun Xie¹, Xingquan Zhang¹, Baolun He^2,*, Ningyu Zheng², Yuqiang Xu^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1385-1395, 2023, DOI:10.32604/fdmp.2023.025454

Abstract The optimization of methods for the quantitative evaluation of risks in drilling engineering is an effective means to ensure safety in situations where high temperature and high pressure blocks are considered. In such a context, this study analyzes the complexity of the drilled wells in such blocks. It is shown that phenomena such as well kick, loss, circulation, and sticking, are related to the imbalance of wellbore pressure. A method for risk quantitative evaluation is proposed accordingly. The method is used to evaluate the risk for 9 drilled wells. By comparing the predictions of the method with actual historical data… More > Graphic Abstract

Xin Huang^1,*, Yunpeng Jiang¹, Daowu Huang¹, Xianke He¹, Xianguo Zhang², Ping Guo³

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.6, pp. 1679-1691, 2023, DOI:10.32604/fdmp.2023.025312

Abstract

The seepage mechanism plays a crucial role in low-permeability gas reservoirs. Compared with conventional gas reservoirs, low-permeability sandstone gas reservoirs are characterized by low porosity, low permeability, strong heterogeneity, and high water saturation. Moreover, their percolation mechanisms are more complex. The present work describes a series of experiments conducted considering low-permeability sandstone cores under pressure-depletion conditions (from the Xihu Depression in the East China Sea Basin). It is shown that the threshold pressure gradient of a low-permeability gas reservoir in thick layers is positively correlated with water saturation and negatively correlated with permeability and porosity. The reservoir stress sensitivity is… More >