Hamidreza Khodayari, Fathollah Ommi and Zoheir Saboohi
The purpose of this paper is to review the applications of the chemical reactor network (CRN) approach for modeling the combustion in gas turbine combustors and classify the CRN…
Abstract
Purpose
The purpose of this paper is to review the applications of the chemical reactor network (CRN) approach for modeling the combustion in gas turbine combustors and classify the CRN construction methods that have been frequently used by researchers.
Design/methodology/approach
This paper initiates with introducing the CRN approach as a practical tool for precisely predicting the species concentrations in the combustion process with lower computational costs. The structure of the CRN and its elements as the ideal reactors are reviewed in recent studies. Flow field modeling has been identified as the most important input for constructing the CRNs; thus, the flow field modeling methods have been extensively reviewed in previous studies. Network approach, component modeling approach and computational fluid dynamics (CFD), as the main flow field modeling methods, are investigated with a focus on the CRN applications. Then, the CRN construction approaches are reviewed and categorized based on extracting the flow field required data. Finally, the most used kinetics and CRN solvers are reviewed and reported in this paper.
Findings
It is concluded that the CRN approach can be a useful tool in the entire process of combustion chamber design. One-dimensional and quasi-dimensional methods of flow field modeling are used in the construction of the simple CRNs without detailed geometry data. This approach requires fewer requirements and is used in the initial combustor designing process. In recent years, using the CFD approach in the construction of CRNs has been increased. The flow field results of the CFD codes processed to create the homogeneous regions based on construction criteria. Over the past years, several practical algorithms have been proposed to automatically extract reactor networks from CFD results. These algorithms have been developed to identify homogeneous regions with a high resolution based on the splitting criteria.
Originality/value
This paper reviews the various flow modeling methods used in the construction of the CRNs, along with an overview of the studies carried out in this field. Also, the usual approaches for creating a CRN and the most significant achievements in this field are addressed in detail.
Details
Keywords
Hamidreza Khalili and Ardalan Sameti
This study aims to measure the quality of services provided to elderly people at the most crowded governmental ambulatory clinics of Tehran Province using the SERVQUAL scale…
Abstract
Purpose
This study aims to measure the quality of services provided to elderly people at the most crowded governmental ambulatory clinics of Tehran Province using the SERVQUAL scale (Study 1). Moreover, the research indicates the medicine reimbursement criteria to inform the decision-makers of public health insurance organizations using the Borda method (Study 2).
Design/methodology/approach
This study was done as a cross-sectional research on 425 elderly patients who came to the clinics during 2014 and 2015. Finally, using the paired t-test, Friedman test, Borda method, SPSS, Matlab software and Delphi method, the collected data were analysed.
Findings
Regarding the perceived quality, the services assurance dimension was ranked as having the highest quality (4.48) and the accessibility dimension as the lowest one (3.22). Based on the Borda method, the most important criterion for the Iranian health insurance companies to accept a medicine in their reimbursement list is the “life-threatening conditions” factor. On the other hand, “evidence quality” is accounted as the fifth important factor.
Research limitations/implications
The main limitation was the senility of participants that makes it difficult for understanding and completing the questionnaires.
Practical implications
The results can be useful for healthcare policy makers and related authorities. Besides, public health insurers can use the findings for decision-making about the elderly diseases and the problems such as the medical expenses.
Originality/value
The present research has been done in a two-year time frame, and it is more recent than other related studies. Thus, the results are far more authentic and applicable.