Esmail Lakzian, Mostafa Ramezani, Sima Shabani, Fahime Salmani, Miroslaw Majkut and Heuy Dong Kim
The purpose of this study is to model steam condensing flows through steam turbine blades and find the most suitable condensation model to predict the condensation phenomenon.
Abstract
Purpose
The purpose of this study is to model steam condensing flows through steam turbine blades and find the most suitable condensation model to predict the condensation phenomenon.
Design/methodology/approach
To find the most suitable condensation model, five nucleation equations and four droplet growth equations are combined, and 20 cases are considered for modelling the wet steam flow through steam turbine blades. Finally, by the comparison between the numerical results and experiments, the most suitable case is proposed. To find out whether the proposed case is also valid for other boundary conditions and geometries, it is used to simulate wet steam flows in de Laval nozzles.
Findings
The results indicate that among all the cases, combining the Hale nucleation equation with the Gyarmathy droplet growth equation results in the smallest error in the simulation of wet steam flows through steam turbine blades. Compared with experimental data, the proposed model’s relative error for the static pressure distribution on the blade suction and pressure sides is 2.7% and 2.3%, respectively, and for the liquid droplet radius distribution it totals to 1%. This case is also reliable for simulating condensing steam flows in de Laval nozzles.
Originality/value
The selection of an appropriate condensation model plays a vital role in the simulation of wet steam flows. Considering that the results of numerical studies on condensation models in recent years have not been completely consistent with the experiments and that there are still uncertainties in this field, further studies aiming to improve condensation models are of particular importance. As condensation models play an important role in simulating the condensation phenomenon, this research can help other researchers to better understand the purpose and importance of choosing a suitable condensation model in improving the results. This study is a significant step to improve the existing condensation models and it can help other researchers to gain a revealing insight into choosing an appropriate condensation model for their simulations.
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Mitra Shabani Nashtaee, Kambiz Heidarzadeh Hanzaei and Yazdan Mansourian
The purpose of this paper is to identify the best interactions between sales promotion and advertisement plans as the resources of the brand attachment and its consequences in…
Abstract
Purpose
The purpose of this paper is to identify the best interactions between sales promotion and advertisement plans as the resources of the brand attachment and its consequences in durable and fast-moving consumer goods.
Design/methodology/approach
The mixed methods research in the form of qualitative approach, using a phenomenological method and quantitative approach, using three experimental studies of factorial design types and a structural equation modeling method, have been used in this research.
Findings
The fit of plans to achieve the brand attachment is similar in both product categories. The financial gift, with the ability of liquidity and variety of shopping, fits with the advertisement messages at a high construal level and high argument strength. However, the financial gift, with the ability of purchase from particular stores, fits with the advertisement messages at the low construal level and high argument strength. Moreover, in both product categories, the brand attachment leads to the emotional and cognitive consequences.
Originality/value
This research provides experimental support with actual experiences to create a fit in marketing communication plans in order to achieve a lasting and strong relationship. Therefore, this paper offers a valuable insight relating to financial gifts and advertisement messages and their effects on consumers’ behavior. It can also be used by other managers and researchers to assess their communication options.
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Ab Kasaeian, Reza Daneshazarian, Fathollah Pourfayaz, Sahar Babaei, Mojgan Sheikhpour and Shima Nakhjavani
Because of its increased absorptance in fluid and reduced heat loss, direct absorption nanofluid (DANF) is receiving intense interest as an efficient way to harvest solar energy…
Abstract
Purpose
Because of its increased absorptance in fluid and reduced heat loss, direct absorption nanofluid (DANF) is receiving intense interest as an efficient way to harvest solar energy. This work aims to investigate, for the first time, the application of DANF in parabolic trough collectors (PTC), a promising collector for solar thermal systems.
Design/methodology/approach
A representative flow and heat transfer study of different fluids in a straight tube is conducted, and the basic energy equation and radiative transfer equations are numerically solved to obtain the fluid temperature distribution and energy conversion efficiency. Ethylene glycol (EG) and different concentrations of (i.e., 0.1-0.6 per cent) multi-wall carbon nanotubes (MWCNT) in EG are used as sample fluids. Four cases are studied for a traditional PTC (i.e., using metal tube) and a direct absorption PTC (i.e., using transparent tube) including a bare tube, a tube with an air-filled glass envelope and a tube with vacuumed glass envelop. The numerical results are verified by an experimental study using a copper-glass absorber tube, which reveals the good potential of DANFs.
Findings
Compared with a conventional PTC, using DANF shows an increase of 8.6 per cent and 6.5 K, respectively, in thermal efficiency and outlet temperature difference at a volume fraction (0.5 per cent) of nanoparticles. The results also show that the improvement in solar efficiency increases with increasing particle concentrations, and the vacuum insulated case has the highest efficiency.
Originality/value
In all previous studies, an important section was missing as the effect of photons on the direct solar absorption trough collector, which is considered in this study. This paper proposes a new concept of using direct solar absorption nanofluids for concentrated solar collectors and analyzes the performance of both absorptance and transmittance efficiency considerations. To reveal the potential of the new concept, an analytical model based on energy balance is developed, and two case studies are performed.
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Javed Aslam, Aqeela Saleem and Yun Bae Kim
This study aims to proposed that blockchain helps the organization improve supply chain (SC) performance by improving integration, agility and security through real-time…
Abstract
Purpose
This study aims to proposed that blockchain helps the organization improve supply chain (SC) performance by improving integration, agility and security through real-time information sharing, end-to-end visibility, transparency, data management, immutability, irrevocable information and cyber-security platforms.
Design/methodology/approach
This study has made an initial effort toward proposing a framework that shows the problems and challenges for the O&G SC under its segments (upstream, midstream and downstream) and provides the interlink among blockchain properties for SCM problems. SC managers were selected for survey questionnaires from the Pakistan O&G industries.
Findings
This study analyzes the impact of blockchain-enabled SC on firm performance with an understanding of the SC robustness capabilities as a mediator. The result revealed that the SC manager believes that the blockchain-enabled SC has a positive and significant on firm performance and robustness capabilities.
Research limitations/implications
Blockchain technology is reflected as high-tech to support the firm process, responses and methods. The technology helps eliminate bottlenecks, avoid uncertainties and improve decision-making, leading to improved SC functions. This study guides managers about the potential problems of existing SC and how blockchain solves SC problems more effectively.
Originality/value
The oil and gas (O&G) sectors are neglected by researchers, and there are limited studies on O&G supply chain management (SCM). Additionally, no empirical evidence suggests implementing blockchain for O&G as a solution for potential problems. Furthermore, present the roadmap to other industries those having complex SC networks for the implication of blockchain to improve the SC performance.