scholarly journals Evaluating the effects of microphysical complexity in idealised simulations of trade wind cumulus using the Factorial Method

2011 ◽  
Vol 11 (6) ◽  
pp. 2729-2746 ◽  
Author(s):  
C. Dearden ◽  
P. J. Connolly ◽  
T. W. Choularton ◽  
P. R. Field
Keyword(s):  
Model Development ◽  
Trade Wind ◽  
One Dimensional ◽  
Surface Precipitation ◽  
Factorial Method ◽  
Modelling Framework ◽  
Development Tool ◽  
Single Moment ◽  
Kinematic Modelling ◽  
The Impact

Abstract. The effect of microphysical and environmental factors on the development of precipitation in warm idealised cloud is explored using a kinematic modelling framework. A simple one-dimensional column model is used to drive a suite of microphysics schemes including a flexible multi-moment bulk scheme (including both single and dual moment cloud liquid water) and a state-of-the-art bin-resolved scheme with explicit treatments of liquid and aerosol. The Factorial Method is employed to quantify and compare the sensitivities of each scheme under a set of controlled conditions, in order to isolate the effect of additional microphysical complexity in terms of the impact on surface precipitation. At relatively low updraught speeds, the sensitivity of the bulk schemes was found to depend on the assumptions made with regards the treatment of droplet activation. It was possible to achieve a much closer agreement between the single and dual moment bulk schemes by tuning the specified droplet number concentration in the single moment scheme, suggesting that a diagnostic representation of droplet number may be an acceptable alternative to the more expensive prognostic option. However the effect of changes in CCN concentration were found to produce a relatively stronger effect on precipitation in the bulk schemes compared to the bin scheme; this is believed to be a consequence of differences in the treatment of drop growth by collision and coalescence. Collectively, these results demonstrate the usefulness of the Factorial Method as a model development tool for quantitatively comparing and contrasting the behaviour of microphysics schemes of differing levels of complexity within a specified parameter space.

scholarly journals Evaluating the effects of microphysical complexity in idealised simulations of trade wind cumulus using the Factorial Method

2010 ◽  
Vol 10 (10) ◽  
pp. 23497-23537 ◽  
Author(s):  
C. Dearden ◽  
P. J. Connolly ◽  
T. W. Choularton ◽  
P. R. Field
Keyword(s):  
State Of The Art ◽  
Model Development ◽  
Cloud Base ◽  
Trade Wind ◽  
One Dimensional ◽  
Surface Precipitation ◽  
Factorial Method ◽  
Modelling Framework ◽  
Development Tool ◽  
The Impact

Abstract. The effect of microphysical and environmental factors on the development of precipitation in warm idealised clouds are explored using an idealised process modelling framework. A simple one-dimensional column model is used to drive a suite of microphysics schemes including a flexible multi-moment bulk scheme (including both single and dual moment liquid water) and a state-of-the-art bin-resolved scheme with explicit treatments of liquid and aerosol. The Factorial Method is employed to quantify and compare the sensitivities of each scheme under a set of controlled conditions, in order to isolate the effect of additional microphysical complexity in terms of the impact on surface precipitation. For the schemes considered, and in the absence of entrainment, surface precipitation totals were found to depend increasingly on the meteorological conditions as the level of microphysical complexity is increased. The dual-moment liquid bulk scheme was shown to provide the best agreement with the bin scheme when the cloud base updraught speeds are relatively weak. At higher updraughts, all schemes show that the sensitivity to the magnitude of vertical velocity reduces dramatically, and any subsequent change in precipitation is governed almost entirely by the change in aerosol concentration. However the effect of changes in temperature were found to be underestimated in the bulk schemes compared to the bin scheme; this can be accounted for through differences in the depletion of rain below cloud base by evaporation. Collectively, these results demonstrate the usefulness of the Factorial Method as a model development tool for quantitatively comparing and contrasting the behaviour of microphysics schemes of differing levels of complexity within a specified parameter space.

Performance Modeling of Desiccant Wheels: 1 — Model Development

2008 ◽  
Author(s):  
Chaoqin Zhai ◽  
David H. Archer ◽  
John C. Fischer
Keyword(s):  
Model Development ◽  
Axial Direction ◽  
Performance Model ◽  
Design Parameters ◽  
Residual Water ◽  
One Dimensional ◽  
Operating Variables ◽  
Steady State Operation ◽  
Rotary Speed ◽  
The Impact

This paper presents the development of an equation based model to simulate the combined heat and mass transfer in the desiccant wheels. The performance model is one dimensional in the axial direction. It applies a lumped formulation in the thickness direction of the desiccant and the substrate. The boundary conditions of this problem represent the inlet outside/process and building exhaust/regeneration air conditions as well as the adiabatic condition of the two ends of the desiccant composite. The solutions of this model are iterated until the wheel reaches periodic steady state operation. The modeling results are obtained as the changes of the outside/process and building exhaust/regeneration air conditions along the wheel depth and the wheel rotation. This performance model relates the wheel’s design parameters, such as the wheel dimension, the channel size and the desiccant properties, and the wheel’s operating variables, such as the rotary speed and the regeneration air flowrate, to its operating performance. The impact of some practical issues, such as wheel purge, residual water in the desiccant and the wheel supporting structure, on the wheel performance has also been investigated.

A Physics-Based Dynamic Model for Boilers: Part 1 — Model Development and Validation

2017 ◽  
Author(s):  
Matthew J. Blom ◽  
Michael J. Brear ◽  
Chris G. Manzie ◽  
Ashley P. Wiese
Keyword(s):  
Steady State ◽  
Power Plant ◽  
Electrical Power ◽  
Model Development ◽  
Two Phase ◽  
One Dimensional ◽  
Modelling Framework ◽  
Singular Perturbation Analysis ◽  
Fluid Properties ◽  
Development And Validation

This paper is the first part of a two part study that develops, validates and integrates a one-dimensional, physics-based, dynamic boiler model suitable for application with model based control. Part 1 of this study extends and validates the existing, higher order modelling framework of Badmus et. al. [1] to boilers. This requires derivation of particular, one-dimensional forms of the equations for heat, mass and momentum transfer in single (liquid and gas) phase and two phase fluids with real fluid properties. The so-called ‘forcing term’ mapping functions in these equations only require knowledge of steady state system behaviour, and so can be obtained from steady state measurements throughout the boiler system. Additional models are also presented for other boiler components, including the steam drum in sub-critical boilers. The overall framework is then used to develop and validate a model of a GW scale, sub-critical boiler in an operating, electrical power plant. Overall, the model achieves reasonable agreement with the power plant dynamics during normal transient operations, including acceptable tracking of the drum dynamics and the steam at the boiler outlet. As such, this modelling framework appears suitable for developing models of sufficient fidelity yet retain an appropriate form for model reduction using singular perturbation analysis techniques, as demonstrated in Part 2 [2] of this study.

scholarly journals On the Fidelity of Large-Eddy Simulation of Shallow Precipitating Cumulus Convection

2011 ◽  
Vol 139 (9) ◽  
pp. 2918-2939 ◽  
Author(s):  
Georgios Matheou ◽  
Daniel Chung ◽  
Louise Nuijens ◽  
Bjorn Stevens ◽  
Joao Teixeira
Keyword(s):  
Large Eddy Simulation ◽  
Liquid Water ◽  
Cloud Cover ◽  
Scale Model ◽  
Trade Wind ◽  
Numerical Dissipation ◽  
Surface Precipitation ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Impact

The present study considers the impact of various choices pertaining to the numerical solution of the governing equations on large-eddy simulation (LES) prediction and the association of these choices with flow physics. These include the effect of dissipative versus nondissipative advection discretizations, different implementations of the constant-coefficient Smagorinsky subgrid-scale model, and grid resolution. Simulations corresponding to the trade wind precipitating shallow cumulus composite case of the Rain in Cumulus over the Ocean (RICO) field experiment were carried out. Global boundary layer quantities such as cloud cover, liquid water path, surface precipitation rate, power spectra, and the overall convection structure were used to compare the effects of different discretization implementations. The different discretization implementations were found to exert a significant impact on the LES prediction even for the cases where the process of precipitation was not included. Increasing numerical dissipation decreases cloud cover and surface precipitation rates. For nonprecipitating cases, grid convergence is achieved for grid spacings of 20 m. Cloud cover was found to be particularly sensitive, exhibiting variations between different resolution runs even when the mean liquid water profile had converged.

Interaction Process Model – ESM Quality Model Development Tool

2020 ◽  
Vol 25 (1) ◽  
pp. 10-17
Author(s):  
B.V. Boytsov ◽  
◽  
G.S. Zhetessova ◽  
M.K. Ibatov ◽  
◽  
...  
Keyword(s):  
Process Model ◽  
Swot Analysis ◽  
Statistical Data ◽  
Model Development ◽  
Interaction Process ◽  
Educational Process ◽  
Quality Model ◽  
Development Tool ◽  
The Republic ◽  
Education Science

The article discusses the methodology and provides the results of a multivariate SWOT analysis for a scientific and manufacturing educational process based on a set of regulatory and strategic documents, statistical data of the Republic of Kazakhstan; The main conclusions and description of the generated matrices for the subjects of interaction within the hierarchical triangle «Education – Science – Manufacturing (ESM)» are given.

scholarly journals Sustainable Tourism, Economic Growth and Employment—The Case of the Wine Routes of Spain

2021 ◽  
Vol 13 (13) ◽  
pp. 7164
Author(s):  
Guillermo Vázquez Vicente ◽  
Victor Martín Barroso ◽  
Francisco José Blanco Jiménez
Keyword(s):  
Economic Growth ◽  
Economic Impact ◽  
Rural Areas ◽  
Local Development ◽  
Tourism Industry ◽  
Wine Tourism ◽  
Development Tool ◽  
The Us ◽  
The Impact ◽  
Positive Effect

Tourism has become a priority in national and regional development policies and is considered a source of economic growth, particularly in rural areas. Nowadays, wine tourism is an important form of tourism and has become a local development tool for rural areas. Regional tourism development studies based on wine tourism have a long history in several countries such as the US and Australia, but are more recent in Europe. Although Spain is a leading country in the tourism industry, with an enormous wine-growing tradition, the literature examining the economic impact of wine tourism in Spanish economy is scarce. In an attempt to fill this gap, the main objective of this paper is to analyze the impact of wine tourism on economic growth and employment in Spain. More specifically, by applying panel data techniques, we study the economic impact of tourism in nine Spanish wine routes in the period from 2008 to 2018. Our results suggest that tourism in these wine routes had a positive effect on economic growth. However, we do not find clear evidence of a positive effect on employment generation.

scholarly journals Attributional & Consequential Life Cycle Assessment: Definitions, Conceptual Characteristics and Modelling Restrictions

2021 ◽  
Vol 13 (13) ◽  
pp. 7386
Author(s):  
Thomas Schaubroeck ◽  
Simon Schaubroeck ◽  
Reinout Heijungs ◽  
Alessandra Zamagni ◽  
Miguel Brandão ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Environmental Impact ◽  
Product Life Cycle ◽  
Sustainability Assessment ◽  
Consequential Life Cycle Assessment ◽  
Modelling Framework ◽  
Potential Environmental Impact ◽  
Reference Environment ◽  
The Impact

To assess the potential environmental impact of human/industrial systems, life cycle assessment (LCA) is a very common method. There are two prominent types of LCA, namely attributional (ALCA) and consequential (CLCA). A lot of literature covers these approaches, but a general consensus on what they represent and an overview of all their differences seems lacking, nor has every prominent feature been fully explored. The two main objectives of this article are: (1) to argue for and select definitions for each concept and (2) specify all conceptual characteristics (including translation into modelling restrictions), re-evaluating and going beyond findings in the state of the art. For the first objective, mainly because the validity of interpretation of a term is also a matter of consensus, we argue the selection of definitions present in the 2011 UNEP-SETAC report. ALCA attributes a share of the potential environmental impact of the world to a product life cycle, while CLCA assesses the environmental consequences of a decision (e.g., increase of product demand). Regarding the second objective, the product system in ALCA constitutes all processes that are linked by physical, energy flows or services. Because of the requirement of additivity for ALCA, a double-counting check needs to be executed, modelling is restricted (e.g., guaranteed through linearity) and partitioning of multifunctional processes is systematically needed (for evaluation per single product). The latter matters also hold in a similar manner for the impact assessment, which is commonly overlooked. CLCA, is completely consequential and there is no limitation regarding what a modelling framework should entail, with the coverage of co-products through substitution being just one approach and not the only one (e.g., additional consumption is possible). Both ALCA and CLCA can be considered over any time span (past, present & future) and either using a reference environment or different scenarios. Furthermore, both ALCA and CLCA could be specific for average or marginal (small) products or decisions, and further datasets. These findings also hold for life cycle sustainability assessment.

scholarly journals Modeling Building Stock Development

2021 ◽  
Vol 13 (2) ◽  
pp. 723
Author(s):  
Antti Kurvinen ◽  
Arto Saari ◽  
Juhani Heljo ◽  
Eero Nippala
Keyword(s):  
Model Development ◽  
Housing Demand ◽  
Quality Data ◽  
Building Stock ◽  
Test Arena ◽  
Climate Targets ◽  
Wide Range ◽  
Key Variables ◽  
The Impact

It is widely agreed that dynamics of building stocks are relatively poorly known even if it is recognized to be an important research topic. Better understanding of building stock dynamics and future development is crucial, e.g., for sustainable management of the built environment as various analyses require long-term projections of building stock development. Recognizing the uncertainty in relation to long-term modeling, we propose a transparent calculation-based QuantiSTOCK model for modeling building stock development. Our approach not only provides a tangible tool for understanding development when selected assumptions are valid but also, most importantly, allows for studying the sensitivity of results to alternative developments of the key variables. Therefore, this relatively simple modeling approach provides fruitful grounds for understanding the impact of different key variables, which is needed to facilitate meaningful debate on different housing, land use, and environment-related policies. The QuantiSTOCK model may be extended in numerous ways and lays the groundwork for modeling the future developments of building stocks. The presented model may be used in a wide range of analyses ranging from assessing housing demand at the regional level to providing input for defining sustainable pathways towards climate targets. Due to the availability of high-quality data, the Finnish building stock provided a great test arena for the model development.

Altitude Effects on the Performance of Small Radial Turbomachinery: Part I — Compressor Impellers

2016 ◽  
Author(s):  
Dries Verstraete ◽  
Kjersti Lunnan
Keyword(s):  
Reynolds Number ◽  
Performance Analysis ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
Unmanned Aircraft ◽  
Good Match ◽  
One Dimensional ◽  
Design Changes ◽  
Current Article ◽  
The Impact

Small unmanned aircraft are currently limited to flight ceilings below 20,000 ft due to the lack of an appropriate propulsion system. One of the most critical technological hurdles for an increased flight ceiling of small platforms is the impact of reduced Reynolds number conditions at altitude on the performance of small radial turbomachinery. The current article investigates the influence of Reynolds number on the efficiency and pressure ratio of two small centrifugal compressor impellers using a one-dimensional meanline performance analysis code. The results show that the efficiency and pressure ratio of the 60 mm baseline compressor at the design rotational speed drops with 6–9% from sea-level to 70,000 ft. The impact on the smaller 20 mm compressor is slightly more pronounced and amounts to 6–10%. Off-design changes at low rotational speeds are significantly higher and can amount to up to 15%. Whereas existing correlations show a good match for the efficiency drop at the design rotational speed, they fail to predict efficiency changes with rotational speed. A modified version is therefore proposed.

Sign in / Sign up

Export Citation Format

Share Document