M.A. Habib, R. Ben‐Mansour, H.M. Badr, S.A.M. Said and S.S. Al‐Anizi
In oil and gas industries, the presence of sand particles in produced oil and natural gas represents a major concern because of the associated erosive wear occurring in various…
Abstract
Purpose
In oil and gas industries, the presence of sand particles in produced oil and natural gas represents a major concern because of the associated erosive wear occurring in various flow passages. Erosion in the tube entrance region of a typical shell and tube heat exchanger is numerically predicted.
Design/methodology/approach
The erosion rates are obtained for different flow rates and particle sizes assuming low particle concentration. The erosion prediction is based on using a mathematical model for simulating the fluid velocity field and another model for simulating the motion of solid particles. The fluid velocity (continuous phase) model is based on the solution of the time‐averaged governing equations of 3D turbulent flow while the particle‐tracking model is based on the solution of the governing equation of each particle motion taking into consideration the viscous and gravity forces as well as the effect of particle rebound behavior.
Findings
The results show that the location and number of eroded tubes depend mainly on the particle size and velocity magnitude at the header inlet. The rate of erosion depends exponentially on the velocity. The particle size shows negligible effect on the erosion rate at high velocity values and the large‐size particles show less erosion rates compared to the small‐size particles at low values of inlet flow velocities.
Originality/value
In oil and gas industries, the presence of sand particles in produced oil and natural gas represents a major concern because of the associated erosive wear occurring in various flow passages. The results indicate that erosion in shell and tube heat exchanger can be minimized through the control of velocity inlet to the header.
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Srikar Sarma Kona, Navdeep Sharma Dugala and Gurmeet Singh
This study aims to investigate the erosion wear rate of a stainless steel automobile exhaust manifold, both computationally and physically.
Abstract
Purpose
This study aims to investigate the erosion wear rate of a stainless steel automobile exhaust manifold, both computationally and physically.
Design/methodology/approach
The experiment was performed on a motorcycle exhaust manifold as well as on a 3D model, created using SolidWorks 2022 CAD software. The analysis was later achieved using ANSYS 19.2 simulation software using Fluent – code.
Findings
The analysis of solid particle erosion in the exhaust manifold revealed that erosion wear is concentrated predominantly at the extrados of the manifold, with the most significant wear occurring at the lowermost bend. The erosion wear rate increases with larger particulate sizes and varies among bends, with negligible wear observed in straight pipes. The SEM analysis further confirmed surface degradation, with rugged textures, pits and grooves indicating abrasive wear. Spine-like structures and fractured soot particles suggest erosive and abrasive forces caused by high-speed contact of exhaust gas compounds. Energy dispersive X-ray spectroscopy revealed significant carbon abundance, indicating carbonaceous compounds from fuel combustion, along with notable amounts of oxygen and iron, typical of oxidized metallic constituents. The discrete phase modeling (DPM) analysis highlighted peak particulate matter deposition at the first bend exit, with maximum concentrations observed at specific angles. This deposition is influenced by centrifugal force, leading to increased PM concentration at outer bend walls. Velocity magnitude contours showed asymmetrical flow profiles, with high turbulence levels and secondary flow induced by centrifugal effects in bend areas. Dynamic pressure contours revealed varying pressures at intrados and extrados, with maximum pressure observed at the intrados of the manifold’s bends. These findings provide valuable insights into erosion wear, particulate dispersion and flow dynamics within the exhaust manifold.
Originality/value
The study investigated an automobile exhaust manifold model using ANSYS Fluent code and DPM to analyze erosion wear rate phenomena and its various constituents. This analysis was conducted in comparison with a physically eroded sample. The study offers insights into the mechanism underlying the exhaust manifold of an automobile.
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Zdzislaw Mazur, Rafael Campos‐Amezcua and Alfonso Campos‐Amezcua
This paper aims to validate an axial turbine modified nozzle design, looking for a reduction of the nozzle erosion process during operation in power plants.
Abstract
Purpose
This paper aims to validate an axial turbine modified nozzle design, looking for a reduction of the nozzle erosion process during operation in power plants.
Design/methodology/approach
The approach taken is numerical simulation using the computational fluid dynamics (CFD) tool, comparing original and proposed/modified nozzle designs.
Findings
The paper provides information about how to achieve a solution of the turbine operational problem (abrasive wear) by an analysis of flow patterns under a variety of conditions.
Research limitations/implications
It does not give a detailed interpretation of flow behaviour due to the lack of validation data.
Practical implications
A very useful flow simulation methodology that can be used in industry is provided.
Originality/value
The proposed design modification of an axial turbine nozzle with the aid of CFD simulation has not been performed yet. This paper investigates the possibility of nozzle erosion reduction by modifying local flow patterns.
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The purpose of this paper is to develop a procedure for deciding on the limits of initial clearance to which tubesheet holes can be enlarged before replacement in heat exchanger…
Abstract
Purpose
The purpose of this paper is to develop a procedure for deciding on the limits of initial clearance to which tubesheet holes can be enlarged before replacement in heat exchanger maintenance.
Design/methodology/approach
An empirical model that relates the hardness of roller expanded tubes and ligaments to initial clearance is developed from experimental data to predict the extent of tolerable levels of over‐enlargement of tubesheet holes before the joint loses its structural integrity. The developed model serves as an additional criterion to decide whether to keep or discard a tubesheet having over‐enlarged holes during heat exchanger maintenance.
Findings
The current industrial criterion does not directly include the effect of material degradation for over‐enlarged holes. The empirical models indicate that both tubes and ligaments suffer strain hardenings. A new procedure is proposed to supplement the current industrial criterion.
Practical implications
The procedure will assist maintenance managers/engineers in deciding on the replacement of heat exchanger tubesheets. The combined criteria will have an impact on the cost of heat exchanger maintenance and plant downtime.
Originality/value
The procedure proposed in this paper adds to the industrial criterion another one that caters for the degradation in properties that the tube, tubesheet, and surrounding ligaments will be subjected to during roller expansion. In other words, it considers the strain hardening of the tube and tubesheet materials in setting the initial clearance between the tube and tubesheet that ensures adequate joint integrity.
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Duha Alsmadi, Ali Maqousi and Tala Abuhussein
Due to the lack of awareness and poor cybersecurity practices that pose cyber threats during COVID-19 time, this research aims to explore user's attitude toward engaging in…
Abstract
Purpose
Due to the lack of awareness and poor cybersecurity practices that pose cyber threats during COVID-19 time, this research aims to explore user's attitude toward engaging in proactive cybersecurity awareness behavior.
Design/methodology/approach
Based on the theory of planned behavior, the relationship between multiple factors and their influence on the attitude is explored. A survey-based approach was utilized to collect responses and a model was proposed and tested on 229 respondents from the University of Petra-Jordan.
Findings
The attitude was significantly influenced by peers' influence and the individuals' cybersecurity threats awareness, especially threats that emerged during the COVID-19 time.
Research limitations/implications
The research benefits decision makers in educational institutions who intend to develop cybersecurity awareness programs and helps them to assess user cybersecurity background weaknesses.
Originality/value
The research is the first to explore users' knowledge dimensions including organizational, information systems and social media as well as peers' influence on cybersecurity awareness. Also, it sheds light on the users’ perception of major cybersecurity hazards in COVID-19 time.