scholarly journals A Numerical Tool for Simultaneous Targeting and Design of Mass Exchange Networks

Design of cost-effective Mass Exchange Networks (MENs) that involves mass integration can help to minimize the amount of mass separating agent (MSA) purchased, waste MSA generated by industries, reduce operating costs and mitigate environmental issues associated with MSA disposal. Design of MENs can be done using graphical and numerical methods, as well as using mathematical modelling. This work describes a new approach for simultaneous targeting and design of MENs in which both targeting and network design stage can be solved in a single template, in order to overcome the limitation of graphical tools such as MENs Composite Curves (CCs) and Grid Diagram. CCs cannot completely map individual rich and lean process streams, or process and utility streams. On the other hand, the numerical technique known as Composition Interval Table (CIT) failed to show individual rich and lean stream mass cascades and cannot be used for MENs design. The newly developed numerical approach in this paper employs the Segregated Composition Interval Table (SECIT) to simultaneously locate mass pinch point, determine the minimum utility targets and perform SECIT Mass Allocation (SMA) that can be used to visualize in SECIT Network Diagram (SND).This work can be applied in industries to minimize liquid waste and reduce environmental pollution A case study is presented to demonstrate the validity and advantages of the proposed approach. This paper also shows that SECIT and SND can be a vital combination of numerical and graphical visualization tools for targeting and design of complex MENs.

2018 ◽  
Vol 122 (1255) ◽  
pp. 1330-1351 ◽  
Author(s):  
Z. Chen ◽  
J. P. Fielding

ABSTRACTZonal Safety Analysis (ZSA) is a major part of the civil aircraft safety assessment process described in Aerospace Recommended Practice 4761 (ARP4761). It considers safety effects that systems/items installed in the same zone (i.e. a defined area within the aircraft body) may have on each other. Although the ZSA may be conducted at any design stage, it would be most cost-effective to do it during preliminary design, due to the greater opportunity for influence on system and structural designs and architecture. The existing ZSA methodology of ARP4761 was analysed, but it was found to be more suitable for detail design rather than preliminary design. The authors therefore developed a methodology that would be more suitable for preliminary design and named it the Preliminary Zonal Safety Analysis (PZSA). This new methodology was verified by means of the use of a case study, based on the NASA N3-X project. Several lessons were learnt from the case study, leading to refinement of the proposed method. These lessons included focusing on the positional layout of major components for the zonal safety inspection, and using the Functional Hazard Analysis (FHA)/Fault Tree Analysis (FTA) to identify system external failure modes. The resulting PZSA needs further refinement, but should prove to be a useful design tool for the preliminary design process.


Author(s):  
Kai Kang ◽  
Rene Chevray

Flow in microchannels is usually slow and the mixing of several fluids is poor if only relying on diffusion. A microchannel mixer with a simple design that is capable of rapid mixing is important for practical applications such as biochemistry analysis. In this study, a general numerical approach to analyze microchannel flow is proposed. The method is based on numerical particle tracking and computer graphics techniques. As a case study, an electro-osmotic driven microchannel mixer is considered with four geometric configurations. The microchannel has a repeated oblique-angled stripe pattern of zeta potential coatings on its floor. The comparison of the particle residence time distributions gives some indication of the mixers’ performances. The efficiency of mixing two flow streams at Pe´clet numbers 2 × 105 and 2 × 104 is then evaluated using the developed procedure. The results indicate that the stripe length ratio is one of the parameters that can be optimized for better mixing. Of the three stripe length ratios evaluated, the configuration with the stripe length ratio 2.0 is found to be the best. In addition, this case study demonstrates that the developed numerical technique is suitable for expeditious parametric optimization of mixer design.


2021 ◽  
Author(s):  
Chandra Shekhar Prasad ◽  
Radek Kolman ◽  
Ludek Pesek

Abstract In this paper a cost effective numerical model for subsonic classical flutter analysis for turbomachinery is presented. The model is based on reduced order aeroelastic modeling (ROAM) approach. The prime objective of the ROAM is to significantly reduce the computational time for flutter analysis of low pressure (LP) stage blades of power turbines at preliminary design stage. A mesh free incompressible fluid solver based on boundary element method(BEM) e.g. 3D panel method is developed. The proposed ROAM is employed to perform subsonic aeroelastic stability analysis in 3D blade cascades. The ROAM simulated results are compared against experimental and high fidelity CFD-CSD model's results. The ROAM estimated results show good agreement with experimental results and prove to be much faster in execution compared to CFD-CSD model. Therefore, this gives designers and engineers a freedom to analyze multiple design iteration in very short time on normal workstation. Thus, the ROAM has immense potential for industrial use as a cost effective and faster numerical tool for design and analysis of more efficient and safer power turbines to meet the future demand of electric energy cheaply, quickly and efficiently.


Buildings ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 66
Author(s):  
Ugochukwu Elinwa ◽  
Cemil Atakara ◽  
Ifeoluwa Ojelabi ◽  
Abiola Abiodun
Keyword(s):  

2021 ◽  
pp. 0308518X2110266
Author(s):  
Neil Argent ◽  
Sean Markey ◽  
Greg Halseth ◽  
Laura Ryser ◽  
Fiona Haslam-McKenzie

This paper is concerned with the socio-spatial and ethical politics of redistribution, specifically the allocation of natural resources rents from political and economic cores to the economic and geographical peripheries whence the resource originated. Based on a case study of the coal seam gas sector in Queensland's Surat Basin, this paper focuses on the operation of the Queensland State Government's regional development fund for mining and energy extraction-affected regions. Employing an environmental justice framework, we critically explore the operation of these funds in ostensibly helping constituent communities in becoming resilient to the worst effects of the ‘staples trap’. Drawing on secondary demographic and housing data for the region, as well as primary information collected from key respondents from mid-2018 to early 2019, we show that funds were distributed across all of the local government areas, and allocated to projects and places primarily on a perceived economic needs basis. However, concerns were raised with the probity of the funds’ administration. In terms of recognition justice, the participation of smaller and more remote towns and local Indigenous communities was hampered by their structural marginalisation. Procedurally, the funds were criticised for the lack of local consultation taken in the development and approval of projects. While spatially concentrated expenditure may be the most cost-effective use of public monies, we argue that grant application processes should be open, transparent and inclusive, and the outcomes cognisant of the developmental needs of smaller communities, together with the need to foster regional solidarity and coherence.


Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1886
Author(s):  
Arezoo Zahediasl ◽  
Amin E. Bakhshipour ◽  
Ulrich Dittmer ◽  
Ali Haghighi

In recent years, the concept of a centralized drainage system that connect an entire city to one single treatment plant is increasingly being questioned in terms of the costs, reliability, and environmental impacts. This study introduces an optimization approach based on decentralization in order to develop a cost-effective and sustainable sewage collection system. For this purpose, a new algorithm based on the growing spanning tree algorithm is developed for decentralized layout generation and treatment plant allocation. The trade-off between construction and operation costs, resilience, and the degree of centralization is a multiobjective problem that consists of two subproblems: the layout of the networks and the hydraulic design. The innovative characteristics of the proposed framework are that layout and hydraulic designs are solved simultaneously, three objectives are optimized together, and the entire problem solving process is self-adaptive. The model is then applied to a real case study. The results show that finding an optimum degree of centralization could reduce not only the network’s costs by 17.3%, but could also increase its structural resilience significantly compared to fully centralized networks.


2011 ◽  
Vol 64 (5) ◽  
pp. 1081-1088 ◽  
Author(s):  
Manfred Kleidorfer ◽  
Wolfgang Rauch

The Austrian standard for designing combined sewer overflow (CSO) detention basins introduces the efficiency of the combined sewer overflows as an indicator for CSO pollution. Additionally criteria for the ambient water quality are defined, which comprehend six kinds of impacts. In this paper, the Austrian legal requirements are described and discussed by means of hydrological modelling. This is exemplified with the case study Innsbruck (Austria) including a description for model building and model calibration. Furthermore an example is shown in order to demonstrate how – in this case – the overall system performance could be improved by implementing a cost-effective rearrangement of the storage tanks already available at the inflow of the wastewater treatment plant. However, this guideline also allows more innovative methods for reducing CSO emissions as measures for better usage of storage volume or de-centralised treatment of stormwater runoff because it is based on a sewer system simulation.


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