Enhanced Heat Collection Element Performance Through Surface Geometry

2011 ◽  
Author(s):  
Rebecca N. Webb ◽  
Julie A. Horvath ◽  
Allen G. Boartfield
Keyword(s):  
Radiative Heat ◽  
Angle Of Incidence ◽  
Steam Generation ◽  
Concentrated Solar Power ◽  
Surface Geometry ◽  
Smooth Test ◽  
Microstructured Surface ◽  
Test Pieces ◽  
Microstructured Surfaces ◽  
The Impact

Concentrated solar power produces electricity by using a mirror to focus sunlight on a fluid filled tube known as a heat collection element. The fluid inside the element is then used as a heat source for steam generation in a conventional steam turbine power plant. It is possible that adding microstructures to the surface of the conventionally smooth heat collection element could improve system efficiency, motivating the need for an improved understanding of the radiation characteristics of a microstructured surface. The goal of this work was to experimentally determine the impact of different microscale geometries on net radiative heat gain when angle of incidence was varied. Five test pieces, one with a smooth surface and four with microstructured surfaces were compared experimentally for a given infrared energy input and flow rate and five different angles of incidence. Over the entire range of angles the microstructured test pieces absorbed more energy than the smooth test piece.

Modeling of Transport During Droplet Deposition and Spreading on Smooth and Microstructured Superhydrophilic Surfaces

2016 ◽  
Author(s):  
Jordan P. Mizerak ◽  
Van P. Carey
Keyword(s):  
Contact Angle ◽  
Contact Angles ◽  
Ansys Fluent ◽  
Effective Contact ◽  
Microstructured Surfaces ◽  
Static Contact ◽  
Droplet Behavior ◽  
Contact Line Pinning ◽  
The Impact ◽  
Superhydrophilic Surfaces

The dynamic behavior of impinging water droplets is studied in the context of varying surface morphologies on smooth and microstructured superhydrophilic surfaces. The goal of this study is to evaluate the capability of contact angle wall adhesion models to accurately produce spreading phenomena seen on a variety of surface types. We analyze macroscale droplet behavior, specifically spreading extent and impinging regime, in situations of varying microscale wetting character and surface morphology. Axisymmetric, volume of fluid (VOF) simulations with static contact angle wall adhesion are conducted in ANSYS Fluent. Simulations are performed on water for low Weber numbers (We<20) on surfaces with features of length scale 5–10μm. Advanced microstructured surfaces consisting of unique wetting characteristics and lengths on each face are also tested. Results show that while the contact angle wall adhesion model shows fair agreement for conventional surfaces, the model underestimates spreading by over 60% for surfaces exhibiting estimated contact angles below approximately 0.5°. Microstructured surfaces adapt the wetting behavior of smooth surfaces with higher effective contact angles based on contact line pinning on morphology features. The propensity of the model to produce Wenzel and Cassie-Baxter states is linked to the spreading radius, introducing an interdependency of microscale wetting and macroscale spreading behavior. Conclusions describing the impact of results on evaporative cooling are also discussed.

scholarly journals Impact study of NOOR 1 project on the Moroccan territorial economic development

2021 ◽  
Vol 6 ◽  
pp. 8
Author(s):  
Amale Laaroussi ◽  
Abdelghrani Bouayad ◽  
Zakaria Lissaneddine ◽  
Lalla Amina Alaoui
Keyword(s):  
Economic Development ◽  
Renewable Energy ◽  
Economic Impact ◽  
Large Scale ◽  
Solar Power ◽  
Local Level ◽  
Concentrated Solar Power ◽  
Professional Literature ◽  
Study Results ◽  
The Impact

Morocco is one of the countries investing more and more in Renewable Energy (RE) technologies to meet the growing demand for energy and ensure the security of supply in this sector. The number of solar projects planned and implemented, as well as solar thermal projects in the form of Concentrating Solar Power (CSP) installations is steadily increasing. Many of these installations are designed as large utility systems. In order to provide strong evidence on local, regional and even national impacts, this article examines the impacts of large-scale renewable energy projects on territorial development, based on a case study of the NOOR 1 (Concentrated Solar Power (CSP)) project in Ouarzazate, Morocco. The data collected during this study, conducted through semi-structured interviews with experts, stakeholders, local community representatives and combined with an analysis of documents provided by the NOOR 1 project managers, investors and consulting firms specialized in the field of Renewable Energy, provide detailed evidence on the type and magnitude of impacts on the economic development of the Moroccan southern region where the NOOR 1 plant is located. The data collected is analyzed using NVIVO software. The study results in a consolidated list of many impacts with varying levels of significance for different stakeholder groups, including farmers, youth, women, community representatives and small and medium firms owners. It should be noted that the importance of analyzing the economic impact of large infrastructure projects is widely recognized, but so far, there is little published in the academic and professional literature on the potential impacts of these projects at the local level. Even less information is available on the local impacts of large-scale project implementation in Morocco. While many macroeconomic studies have fed the recent surge in investment in RE projects with the promise of multiple social, economic, environmental, and even geopolitical benefits at the macro level, public debates and discussions have raised considerable doubts. The question of whether these promises would also leave their marks at the local level has also arisen. Despite these uncertainties, very few academics and practitioners have conducted research to empirically develop a good understanding of the impact of RE projects at the local level. To fill this research gap, the economic impact analysis of NOOR 1 provides a detailed empirical overview, which allows a better understanding of the effects that the infrastructure developments of Concentrated Solar Power (CSP) plants can have on the economic environment in which they are located.

scholarly journals A Comparative Study of Multi-form Steam Generators Using Concentrated Solar Power

2021 ◽  
Vol 88 (2) ◽  
pp. 157-168
Author(s):  
Ayad T. Mustafa ◽  
Mohammed M. Hadi
Keyword(s):  
Renewable Energy ◽  
Cylindrical Cavity ◽  
Steam Generation ◽  
Concentrated Solar Power ◽  
Steam Generators ◽  
Solar Concentrators ◽  
Investment Cost ◽  
High Investment ◽  
Solar Receiver ◽  
Fine Adjustment

Solar energy reaching Earth can be used as promising renewable energy to overcome the challenges of steam generation processes. Solar concentrators suffer from fine adjustment of solar radiation concentration and high investment cost. Therefore, multi-configuration receivers named the cylindrical cavity receiver, helical receiver, and the absorber-evaporator-tank have been manufactured from the coiled copper tube and brass plates, respectively. Then, they are tested and compared to improve the performance of steam generators. The performance of the absorber-evaporator-tank receiver has been compared with the cylindrical cavity receiver and helical receiver for a period from 10 am to 12 pm. The present investigation shows that the boiling point of water increasing when the pressure of generated steam increases particularly inside the coiled tube, which affects the dryness fraction of the generated steam. The present results show that the efficiency of the absorber-evaporator-tank is greater than the cylindrical cavity and helical receivers for the tested period. It is found that the thermal efficiency for the absorber-evaporator-tank doubles at noon, which indicates an effective solar receiver for generating steam.

Designing with pixels: parametric thinking for patterning dynamic building facades

2019 ◽  
Vol 26 (4) ◽  
pp. 668-688
Author(s):  
Zaki Mallasi
Keyword(s):  
Design Thinking ◽  
Real Life ◽  
Digital Design ◽  
Blue Color ◽  
Practical Application ◽  
Surface Geometry ◽  
Content Type ◽  
Building Facade ◽  
Building Facades ◽  
The Impact

Purpose Advances in digital design tools enable exploration and generation of dynamic building facades. However, some processes are formally prescribed and manually driven to only visualize the design concepts. The purpose of this paper is to present a proactive framework for integrating parametric design thinking, paying particular attention to building facade patterning. Design/methodology/approach This work developed the PatternGen© add-on in Autodesk® Revit which utilizes an analytical image data (AID) overlay approach as a data source to dynamically pattern the building facade. The add-on was used to manipulate the placement rules of curtain panels on facade surface geometry. As means of validating this research model, a real-life design project has been chosen to illustrate the practical application of this approach. Feedback and observations from a short end-user questionnaire assessed qualitatively the facade patterning and panelization approach. Findings The proposed merge (or overlay) of AID images can be used as a parametric thinking method rather than just theory to generate and articulate dynamic facade design. The facade panelization responds to an AID that resembles design-performance data (e.g. solar exposure, interior privacy importance and aesthetics). Originality/value This work identifies a form of parametric thinking defined as the expression of geometrical relationships and its configuration dependent on the AID pixel Red Green Blue color source values. In this type of thinking, it explores the impact of the digital process and parametric thinking utility when driven by an AID overlay. The framework highlighted the practical application of AID pixel approach within a digital process to benefit both designers and computational tools developer on emerging design innovations.

The Wear Process Between Normally Impacting Elastic Bodies

1974 ◽  
Vol 96 (4) ◽  
pp. 595-604 ◽  
Author(s):  
P. A. Engel ◽  
R. G. Bayer
Keyword(s):  
Peak Strain ◽  
Impact Wear ◽  
Axially Symmetric ◽  
Surface Geometry ◽  
Normal Impact ◽  
Wear Process ◽  
Surface Fatigue ◽  
Elastic Bodies ◽  
Symmetric Configuration ◽  
The Impact

The wear process between two elastic bodies, repeatedly impacting in an axially symmetric configuration is investigated analytically and experimentally. The mechanism initiating wear is that of surface fatigue, and the paper aims to explain the geometric process of wear formation beyond the “zero wear limit.” In doing so, an engineering, predictive model is sought, whereby the depth of a worn crater is related to the stresses arising during impact and to the number of loading cycles on the specimen. Four major accomplishments are embodied in the paper: (1) the quasi-static analysis of impact on a medium of nonuniform (cratered) surface geometry, (2) a heuristic derivation of the optimum wearpath, (3) derivation of the partial differential equation of normal impact wear, and (4) computation of the impact wear process for two discrete impact wear configurations and comparison of experimental work with the analytical results. The resulting conclusion is that impact wear proceeds at continuously varying curvature until the soft body conforms to the shape of the hard indenter. By equating the hysteretic wear energy with a fraction of the peak strain energy, quantitative wear history predictions are made for discrete geometries, such as a hard sphere impacting against a soft plane. Some experimental results are given between steel and aluminum specimens, confirming the analytical predictions.

The Impact of Hardened Steel Milling Surface Structure on Mould Service Load

2014 ◽  
Vol 800-801 ◽  
pp. 342-347
Author(s):  
Min Li Zheng ◽  
Jin Hui Xu ◽  
Wei Zhang ◽  
Zhao Xing Zhang ◽  
Tong Wu
Keyword(s):  
Hardened Steel ◽  
Surface Load ◽  
Surface Geometry ◽  
Surface Loading ◽  
Machined Surface ◽  
Geometry Model ◽  
Geometry Structure ◽  
Mould Surface ◽  
Service Load ◽  
The Impact

Mould surface loading state is one of the most important factors which would affect the mould performance in the course of service. According to the established hardened steel milling surface geometry model, a bending forming numerical simulation of hardened steel milling is conducted, the influence law of service process surface load state is analyzed under machined surface geometry structure which is formed by different milling parameters. The research results show: surface load concentrated area is mainly focusing on mould edge transition and fillet in the course of service; the surface geometry structure has an important influence on the mould service load in the course of service, service load more smaller which is more helpful to improve the mould service performance in the course of service.

Studies of two-dimensional liquid-wedge impact and their relevance to liquid-drop impact problems

1985 ◽  
Vol 401 (1821) ◽  
pp. 225-249 ◽  
Keyword(s):  
High Speed ◽  
Liquid Drop ◽  
Time History ◽  
Drop Impact ◽  
High Speed Photography ◽  
Two Dimensional ◽  
Surface Geometry ◽  
Repeated Impact ◽  
Liquid Impact ◽  
The Impact

In the initial stage of liquid-drop impact, the contact region expands faster than the wave speed in the liquid. This causes compressible behaviour in the liquid, and high transient pressures. High-velocity jetting results when the wave motion in the liquid overtakes the expanding contact edge and moves up the free surface of the drop. The detailed pressure fields in this early time history of impact have been calculated by Lesser ( Proc . R . Soc . Lond . 377, 289 (1981)) for both two and three-dimensional liquid masses and for targets of finite admittance. An important result is that the edge pressures exceed the central ‘water-hammer’ pressure 3ρ 0 CU i and at the time of shock-detachment approach ca . 3ρ 0 CU i . At this stage the edge pressures, for both spherical drops and two-dimensional liquid wedges, depend only on the impact velocity and the instantaneous angle between the liquid and solid surfaces. This suggests that the essential features of the early stage of liquid impact can be usefully studied by producing impacts with two-dimensional liquid wedges, and predicted data for pressures, shock angles and velocities are presented. Experiments are described for producing impacts with preformed shapes by using water-gelatine mixtures and observing the impact events with high-speed photography. The results confirm the main features of the model and give information on edge pressures, jetting, cavitation in the liquid and the effect of the admittance of the solid. The relevance of the results to the damage and erosion of materials subjected to liquid impact is discussed. In particular, it is possible to explain the apparently low damage-threshold of some materials, the form of damage and its development with repeated impact. The study highlights the importance of the detailed surface geometry in the region of contact.

scholarly journals Small nanoparticles, surface geometry and contact forces

2018 ◽  
Vol 474 (2211) ◽  
pp. 20170723 ◽  
Author(s):  
Yoichi Takato ◽  
Michael E. Benson ◽  
Surajit Sen
Keyword(s):  
Contact Force ◽  
Contact Forces ◽  
Spherical Nanoparticles ◽  
Hertz Contact ◽  
Surface Geometry ◽  
Impact Forces ◽  
Nonlinear Contact ◽  
Amorphous Surface ◽  
The Impact ◽  
Small Nanoparticles

In this molecular dynamics study, we examine the local surface geometric effects of the normal impact force between two approximately spherical nanoparticles that collide in a vacuum. Three types of surface geometries—(i) crystal facets, (ii) sharp edges, and (iii) amorphous surfaces of small nanoparticles with radii R <10 nm—are considered. The impact forces are compared with their macroscopic counterparts described by nonlinear contact forces based on Hertz contact mechanics. In our simulations, edge and amorphous surface contacts with weak surface energy reveal that the average impact forces are in excellent agreement with the Hertz contact force. On the other hand, facet collisions show a linearly increasing force with increasing compression. Our results suggest that the nearly spherical nanoparticles are likely to enable some nonlinear dynamic phenomena, such as breathers and solitary waves observed in granular materials, both originating from the nonlinear contact force.

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