Hao Luo¹, Haibo Deng¹, Honglin Xiao¹, Shaoyang Geng^2,*, Fu Hou¹, Gang Luo¹, Yaqi Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 641-659, 2024, DOI:10.32604/fdmp.2023.043565

Abstract Almost all sandstone reservoirs contain interlayers. The identification and characterization of these interlayers is critical for minimizing the uncertainty associated with oilfield development and improving oil and gas recovery. Identifying interlayers outside wells using identification methods based on logging data and machine learning is difficult and seismic-based identification techniques are expensive. Herein, a numerical model based on seepage and well-testing theories is introduced to identify interlayers using transient pressure data. The proposed model relies on the open-source MATLAB Reservoir Simulation Toolbox. The effects of the interlayer thickness, position, and width on the pressure response are thoroughly investigated. A procedure for… More >

Xin Ai^1,2,*, Mian Chen¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.3, pp. 661-670, 2024, DOI:10.32604/fdmp.2023.026819

Abstract

The efficient development and exploitation of shale oil depends on long-distance horizontal wells. As the degree of cleaning of the wellbore plays a key role in these processes, in this study, this problem is investigated experimentally by focusing on the dimensionless cuttings bed height. A method is proposed to calculate the horizontal-well hydraulic extension taking into account the influence of the wellbore cleaning degree on the wellbore pressure distribution and assess the effect of a variety of factors such as the bottom hole pressure, the circulating pressure drop, the drilling pump performance and the formation properties. The analysis shows that… More >

Yuanyuan Feng^*

Molecular & Cellular Biomechanics, Vol.20, No.2, pp. 97-108, 2023, DOI:10.32604/mcb.2023.045804

Abstract Background: The increasing number of Tai Chi practitioners has led to extensive attention from researchers regarding the role of Tai Chi exercise. Numerous studies have been conducted through various experiments to examine the effects of Tai Chi on physical and mental improvement. Objective: This paper aims to investigate the effect of practicing Tai Chi (eight methods and five steps) on athletes’ body balance control ability from a biomechanical perspective. Methods: Twenty male athletes were randomly divided into two groups. They had no significant differences in age, height, weight, and training time. The Tai Chi group performed Tai Chi (eight methods… More > Graphic Abstract

Huaiyin He¹, Longqing Zou¹, Yanchao Li¹, Yixuan Wang¹, Junxiang Li¹, Huan Wen¹, Bei Chang¹, Lijun Liu^2,*

Energy Engineering, Vol.121, No.1, pp. 111-123, 2024, DOI:10.32604/ee.2023.041010

Abstract Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs, but the interpretation of hydraulic fracture parameters is challenging. The pressure signals after pump shutdown are influenced by hydraulic fractures, which can reflect the geometric features of hydraulic fracture. The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner. In this paper, a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction, perforation friction and fluid loss in fractures. An efficient numerical simulation method is established by using the method of characteristics. Based on this… More >

Mahyar Kargaran^*, Mahmood Farzaneh-Gord

Frontiers in Heat and Mass Transfer, Vol.4, No.1, pp. 1-6, 2013, DOI:10.5098/hmt.v4.1.3007

Abstract Vortex tube is a simple device which separate an inlet gas with a proper pressure into hot and cold flows .This device is well-suited for generating cooling load gas because it provides the cold gas without using any refrigerants . Many research works has been carried out in order to identify the factors which contribute to Vortex tube performance. Here, an experimental study has been made to determine the effect of geometrical (length of vortex tube) and thermo-physical (pressure) parameters on vortex tube performance and air also used as a working fluid. More >

Greg Ball, John Polansky, Tarik Kaya^*

Frontiers in Heat and Mass Transfer, Vol.4, No.1, pp. 1-9, 2013, DOI:10.5098/hmt.v4.1.3002

Abstract The fluid flow and heat transfer in an evaporating extended meniscus are numerically studied. Continuity, momentum, energy equations and the Kelvin-Clapeyron model are used to develop a third order, non-linear ordinary differential equation which governs the evaporating thin film. It is shown that the numerical results strongly depend on the choice of the accommodation coefficient and Hamaker constant as well as the initial perturbations. Therefore, in the absence of experimentally verified values, the numerical solutions should be considered as qualitative at best. It is found that the numerical results produce negative liquid pressures under certain specific conditions. This result may… More >

Benjamin Lepers^a,*, Aditya Putranto^b,c, Martin Umminger^d, Guido Link^a, John Jelonnek^a

Frontiers in Heat and Mass Transfer, Vol.5, pp. 1-11, 2014, DOI:10.5098/hmt.5.13

Abstract The use of high power microwaves to perform explosive spalling of surface concrete is a promising technique with applications in the area of concrete facilities decommissioning. The mechanism that creates explosive spalling is an interactive process of the thermal stress from high temperature gradients and the pore pressure generated from the water vaporization. In order to better predict the total stress distribution, the temperature has to be calculated by including the effect of water vaporization and water transport through a porous medium. In this paper, a one dimensional model solving the heat and diffusion equation for liquid and vapor phase… More >

Swetha Lanka¹, Venkata Subrahmanyam Sajja^1,*, Dhaneshwar Prasad²

Frontiers in Heat and Mass Transfer, Vol.21, pp. 385-405, 2023, DOI:10.32604/fhmt.2023.042544

Abstract An attempt is made to analyse some lubrication characteristics of rigid cylindrical asymmetric rollers under adiabatic and isothermal boundaries with rolling and sliding motion lubricated by a non-Newtonian incompressible Bingham plastic fluid under the behaviour of line contact. Here the lower surface is considered to move quicker than that of the upper surface; and the Roelands viscosity model is considered and assumed to depend upon the fluid pressure and the mean film temperature. The governing equations for fluid flow such as equations of motion with continuity and the momentum energy equation are solved using Runge-Kutta forth order and MATLAB is… More >

Mainak Bhaumik¹, Anirban Sur^2,*, Kavita Dhanawade³

Frontiers in Heat and Mass Transfer, Vol.21, pp. 467-486, 2023, DOI:10.32604/fhmt.2023.044605

Abstract Pin fins are widely used in applications where effective heat transfer is crucial. Their compact design, high surface area, and efficient heat transfer characteristics make them a practical choice for many thermal management applications. But for a high heat transfer rate and lightweight application, aerofoil shape pin fins are a good option. This work focuses on an experimental model analysis of pin-fins with aerofoil shapes. The results were evaluated between perforation, no perforation, inline, and staggered fin configurations. Aluminum is used to make the pin fins array. The experiment is carried out inside a wind tunnel, and the heat supply… More >

Seyed Ehsan Rafiee^*, M. M. Sadeghiazad

Frontiers in Heat and Mass Transfer, Vol.7, pp. 1-15, 2016, DOI:10.5098/hmt.7.13

Abstract The aim of this investigation is study on separation phenomenon inside a special vortex tube affected by structural and physical factors including; throttle diameter, nozzle number and injection pressure as well as the parametric optimization based on separation efficiency using experimental and 3D-CFD methods. The results show that convergent VT with Dth=5.5mm provides 30.01% and 20.04% higher cooling and heating effectiveness compared to basic model. As another result, the higher injection pressure, the higher cooling effectiveness. The cooling effectiveness improves (16.86%) with increase in slot number up to N=4, then decreases. The maximum disagreement between experimental and predicted values is… More >