scholarly journals First results of a model user survey on a micro-scale model data standard

2020 ◽  
Author(s):  
Vivien Voss ◽  
K. Heinke Schlünzen ◽  
David Grawe ◽  
Daniel Heydebreck ◽  
Anette Ganske
Keyword(s):  
Scale Model ◽  
Model Data ◽  
User Survey ◽  
Micro Scale ◽  
Data Standard ◽  
First Results

scholarly journals How to develop and apply a model data standard on microscale model data.

2021 ◽  
Author(s):  
Vivien Voss ◽  
David Grawe ◽  
K. Heinke Schlünzen
Keyword(s):  
Data Dissemination ◽  
Atmospheric Model ◽  
Small Scale ◽  
Building Structures ◽  
Model Output ◽  
Model Data ◽  
Micro Scale ◽  
Data Standard ◽  
Microscale Model ◽  
Scale Modelling

<p>Numerical modeling makes it possible to represent complex processes in small-scale and complex areas like cities. For resolving obstacles, grid sizes in the order of meters are needed. Due to small grid sizes and numerical restrictions, such high-resolution investigations require a great deal of resources. Therefore, a re-use of the results by others would enhance the value of any of these model results. However, the subsequent use of model results is still poorly developed. Comparisons of model data, dissemination of results, or reproduction of simulations are hampered by inconsistent data structures, non-standardized variable names, and lack of information on model setup. In general, to ensure the reusability and accessibility of model data, data standards should be used. The most common data standard for atmospheric model output data are the CF conventions, a data standard for netCDF files, but this standard is currently not extended to cover the model output of obstacle resolving models (ORM).</p><p>The AtMoDat (Atmospheric Model Data) project developed a model data standard (ATMODAT standard) which ensure FAIR (Findability, Accessibility, Interoperability, and Reuse) and well documented data. We involved the micro-scale modelling community in this process with a web based survey (http://uhh.de/orm-survey) to find out which micro-scale ORMs are currently in use, their model specifics (e.g. used grid, coordinate system), and the handling of the model result data. Furthermore, the survey provides the opportunity to include suggestions and ideas, what we should consider in the development of the standard. We already identified typical variables used by ORMs (i.e. building structures, wall temperatures) and will propose them to be included in the CF convention.  The application of this standard is tested on the model output of the ORM MITRAS. The standard and experiences with its application will be presented.</p>

scholarly journals Constraining a complex biogeochemical model for CO<sub>2</sub> and N<sub>2</sub>O emission simulations from various land uses by model–data fusion

2017 ◽  
Vol 14 (14) ◽  
pp. 3487-3508 ◽  
Author(s):  
Tobias Houska ◽  
David Kraus ◽  
Ralf Kiese ◽  
Lutz Breuer
Keyword(s):  
Data Fusion ◽  
Arable Land ◽  
Shallow Groundwater ◽  
Scale Model ◽  
Biogeochemical Model ◽  
N2o Emissions ◽  
Model Errors ◽  
Model Data ◽  
Validation Data ◽  
Fusion Concept

Abstract. This study presents the results of a combined measurement and modelling strategy to analyse N2O and CO2 emissions from adjacent arable land, forest and grassland sites in Hesse, Germany. The measured emissions reveal seasonal patterns and management effects, including fertilizer application, tillage, harvest and grazing. The measured annual N2O fluxes are 4.5, 0.4 and 0.1 kg N ha−1 a−1, and the CO2 fluxes are 20.0, 12.2 and 3.0 t C ha−1 a−1 for the arable land, grassland and forest sites, respectively. An innovative model–data fusion concept based on a multicriteria evaluation (soil moisture at different depths, yield, CO2 and N2O emissions) is used to rigorously test the LandscapeDNDC biogeochemical model. The model is run in a Latin-hypercube-based uncertainty analysis framework to constrain model parameter uncertainty and derive behavioural model runs. The results indicate that the model is generally capable of predicting trace gas emissions, as evaluated with RMSE as the objective function. The model shows a reasonable performance in simulating the ecosystem C and N balances. The model–data fusion concept helps to detect remaining model errors, such as missing (e.g. freeze–thaw cycling) or incomplete model processes (e.g. respiration rates after harvest). This concept further elucidates the identification of missing model input sources (e.g. the uptake of N through shallow groundwater on grassland during the vegetation period) and uncertainty in the measured validation data (e.g. forest N2O emissions in winter months). Guidance is provided to improve the model structure and field measurements to further advance landscape-scale model predictions.

Skin Friction Resistance of Ships

1957 ◽  
Vol 1 (03) ◽  
pp. 3-12
Author(s):  
F. H. Todd
Keyword(s):  
Skin Friction ◽  
Present Status ◽  
Comparative Studies ◽  
Scale Model ◽  
Small Scale ◽  
Model Data ◽  
Towing Tank ◽  
Friction Resistance ◽  
Small Scale Model

The International Towing Tank Conference (ITTC) is to hold its 8th meeting in Madrid in September of this year. One of the subjects to be discussed will be the perennial one of how to estimate the resistance of a ship from that measured on a small-scale model in a towing tank. The Skin Friction Committee of the Conference was charged at the last meeting in Scandinavia in 1954, with reviewing the available data and making recommendations to the Conference in Madrid which will, it is hoped, be universally acceptable. Such a decision would remove one of the principal difficulties experienced in the use of model data in comparative studies. It is believed that a review of the present status of our knowledge in this field may be of interest to the members of the Society at this time.

scholarly journals First results of pipe pile static load test in small laboratory scale

2018 ◽  
Vol 251 ◽  
pp. 04038 ◽  
Author(s):  
Michal Baca ◽  
Jaroslaw Rybak
Keyword(s):  
Static Load ◽  
Axial Loading ◽  
Laboratory Scale ◽  
Load Test ◽  
Scale Model ◽  
Small Scale ◽  
Small Laboratory ◽  
Static Load Test ◽  
First Results ◽  
Load Tests

Presented laboratory testing program of tubular steel piles is a part of a bigger research program which contained static load tests in full scale and numerical simulations of conducted research. The main goal of the research is to compare static load tests with different working conditions of a shaft. The presented small scale model tests are the last part of the research. The paper contains the testing methodology description and first results of model pile axial loading. The static load tests in a small laboratory scale were conducted in a container filled with uniformly compacted medium sand (MSa). The first results of the investigation are presented in this paper, with the comparison of two pile capacities obtained for different roughness of the pile shaft (skin friction). The results are presented as load-displacement curves obtained by means of the Brinch-Hansen 80% method.

Use of Scale-Model Aids in Solution of Complex Air-Flow Design Problem

1965 ◽  
Author(s):  
Arthur Oppenheim ◽  
Frederic M. Oran
Keyword(s):  
Scale Construction ◽  
Scale Model ◽  
Inlet Section ◽  
Engine Test ◽  
Model Data ◽  
Jet Engine ◽  
Basic Fluid ◽  
Air Stream ◽  
Step Procedure ◽  
Selection Of

This paper describes a method used to design the inlet section of a jet-engine test cell. Calculations, accomplished with the use of standard, tabulated flow formulas and coefficients which can be found in basic fluid-flow texts, are shown. The step-by-step procedure enables the reader to use the methods and formulas in this paper as a guide for solving similar problems. Selection of an optimum turning-vane configuration is described herein by the use of tufts of cotton in the air stream of the model. A table is included which compares the model data with actual full-scale construction at various stages.

Borehole dc resistivity response for a transitional invaded zone

Geophysics ◽  
1994 ◽  
Vol 59 (12) ◽  
pp. 1796-1805 ◽  
Author(s):  
K. K. Roy ◽  
D. J. Dutta
Keyword(s):  
Separation Of Variables ◽  
Electrode Array ◽  
Forward Model ◽  
Scale Model ◽  
Model Data ◽  
Mud Cake ◽  
Alternative Approach ◽  
Data Points ◽  
Invaded Zone ◽  
D Model

A borehole direct‐current resistivity boundary value problem for normal and lateral elctrode configuratin is soved assuming axial symmetry. The borehole mud, a flushed zone, an invaded zone, and an unciontaminated zone are all assumed to be present. A linear transition in resistivity is assumed for the invaded zone. Frobenius extended power series and the method of separation of variables are used to solved the 1-D problem. Single-run borehole resistivity sounding and solution of the inverse problem are suggested fo estimatingthe resisitivity of the uncontaminated zone and the radius of invasion. Finite‐difference modeling is dione to estimate the effect of shoulder beds ion borehole sounding. Some of the computed 1-D and 2-D model apparent reisivity curves are compared with the existing scale model data. The analysis reveals that the mud cake effect is negligible for normal and lateral electrode array and the invasion zone thickness is feflected in the forward models. Apparent resistivity curves with and without a transitional invaded zone are well separated. Resistivity departure curves are well separated for fixed resistivity and variable resistivity invaded zone models. A normal electrode configuration can feel the presence of the shoulder bed in a 2-D model when the bed thickness is about 12 time the electrode separation. One‐dimensional ridge regression inversion the synthetic forward model data is presented to suggest an alternative approach for determining the resistivey of the uncontaminated zone ([Formula: see text]) and the radius of invasion [Formula: see text]. We conclude that (1) a single run borehole sounding with 10 or 12 data points from a normal or lateral log may be used, rather than 3 points from a dual laterolog [Formula: see text] tool, for better estimation of [Formula: see text], and (2) a borehole forward model should include a transitional invaded zone. Finally, an alternative approach for the estimation of the radius of invasion is proposed.

A Micro-Scale Model for Fiber Tow Characterization under Nondeterministic Assumption: Longitudinal and Transverse Permeability

2013 ◽  
Vol 554-557 ◽  
pp. 2348-2354 ◽  
Author(s):  
Pierpaolo Carlone ◽  
Gaetano S. Palazzo
Keyword(s):  
Scale Model ◽  
Liquid Composite Molding ◽  
Trial And Error ◽  
Flow Simulations ◽  
Micro Scale ◽  
Multi Scale ◽  
Representative Cell ◽  
Transverse Permeability ◽  
Composite Molding ◽  
Cure Models

Liquid Composite Molding processes are characterized by the impregnation of a dry fibrous perform by means of injection or infusion of a catalyzed resin. In recent years computational flow and cure models allowed for a remarkable time and cost compression in process planning with respect to trial and error procedures. In this contest multi-scale simulative approaches are gaining considerable attention and intriguing results have been recently presented. Most of the proposed models, however, rely on deterministic hypothesis, assuming perfect fiber packing and neglecting dimensional variations between fibers, in strong contrast with experimental observations. In this paper the influence of the stochastic variability of the fiber packing on tow permeability has been investigated by means of a CFD micro scale model. The variability of the microstructure defining the Representative Volume Element has been considered introducing random perturbations of the fiber packing. The components of the permeability tensor, in each case, have then been derived applying the Darcy model to flow simulations through the representative cell.

Acoustic modeling and migration of stacked cross‐hole data

Geophysics ◽  
1988 ◽  
Vol 53 (4) ◽  
pp. 492-500 ◽  
Author(s):  
Xianhuai Zhu ◽  
George A. McMechan
Keyword(s):  
Line Source ◽  
Synthetic Data ◽  
Point Sources ◽  
Scale Model ◽  
Model Data ◽  
Reverse Time ◽  
Imaging Condition ◽  
Surface Survey ◽  
Excitation Time ◽  
And Migration

Prestack computations for cross‐hole data are relatively expensive, as they are for prestack surface survey data. It is therefore of interest to develop methodologies for modeling and processing stacked cross‐hole data. In this context, stacking is over sources, not midpoints. Modeling with a line source produces data that are equivalent (by Huygen’s principle) to those obtained by stacking over a line of point sources. Reverse‐time finite‐difference migration may be applied to the resulting stacked section by generalizing the excitation‐ time imaging condition for a point source to a line source. Illustrations include successful applications to both synthetic data and scale‐model data.

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