scholarly journals CONSIDERATIONS ON FACTORS IN BREAKWATER MDDEL TESTS

1972 ◽  
Vol 1 (13) ◽  
pp. 98
Author(s):  
Yvon Ouellet
Keyword(s):  
Wave Height ◽  
Scale Effects ◽  
Model Tests ◽  
Public Works ◽  
Test Results ◽  
The Subject ◽  
Natural Stones ◽  
Run Up ◽  
The Given ◽  
Standard Weight

In the light of tests on breakwater armor units conducted at Laval University on behalf of the Department of Public Works of Canada, a discussion on various factors involved in model tests on breakwater armor units is presented in comparison with previous studies made on the subject. Tests have been carried out on natural stones, tetrapods and mainly dolosse. Various factors whether they pertain to waves or to the structure are analysed in view of the factors resulting from the interaction of both of them, that is stability of the armor units, damage to the structure or run up of the facing. These factors are the ones for which model tests are conducted. The interpretation of results for the given test conditions should not be evaluated without considering possible scale effects. From the analysis of test results presented by different investigators, a need for the standardization of test results became apparent. Recommendations are made concerning the presentation of results for their future use in engineering design. A standard weight of 100 grs with a standard length of 100 cms for model values are proposed to present the results on a diagram showing significant wave height versus damage, where damage should be expressed in terms of the number of units displaced in the area between + the wave height giving 1% damage.

LARGE SCALE EXPERIMENTS ON EVOLUTION AND RUN-UP OF BREAKING SOLITARY WAVES

2007 ◽  
Vol 01 (03) ◽  
pp. 257-272 ◽  
Author(s):  
KAO-SHU HWANG ◽  
YU-HSUAN CHANG ◽  
HWUNG-HWENG HWUNG ◽  
YI-SYUAN LI
Keyword(s):  
Solitary Wave ◽  
Wave Height ◽  
Solitary Waves ◽  
Water Depth ◽  
Large Scale ◽  
Scale Effects ◽  
Wave Heights ◽  
Run Up ◽  
Hydraulics Laboratory ◽  
The Waves

The evolution and run-up of breaking solitary waves on plane beaches are investigated in this paper. A series of large-scale experiments were conducted in the SUPER TANK of Tainan Hydraulics Laboratory with three plane beaches of slope 0.05, 0.025 and 0.017 (1:20, 1:40 and 1:60). Solitary waves of which relative wave heights, H/h0, ranged from 0.03 to 0.31 were generated by two types of wave-board displacement trajectory: the ramp-trajectory and the solitary-wave trajectory proposed by Goring (1979). Experimental results show that under the same relative wave height, the waveforms produced by the two generation procedures becomes noticeably different as the waves propagate prior to the breaking point. Meanwhile, under the same relative wave height, the larger the constant water depth is, the larger the dimensionless run-up heights would be. Scale effects associated with the breaking process are discussed.

Vortex separator: dimensionless properties and calculation of annual separation efficiencies

1996 ◽  
Vol 33 (9) ◽  
pp. 277-284 ◽  
Author(s):  
Gebhard J. Weiß ◽  
Steven Michelbach
Keyword(s):  
Steady Flow ◽  
Separation Efficiency ◽  
Scale Effects ◽  
Treatment Plant ◽  
Transfer Model ◽  
Test Results ◽  
Combined Sewer Overflows ◽  
Combined Sewer ◽  
Vortex Separator ◽  
The Given

Vortex separators as new devices for combined sewer overflows (CSOs) claim good efficiencies which can be confirmed by laboratory tests. Such model tests are usually performed in reduced scale and under steady-flow conditions. This paper describes a possible way to transfer model test results to the prototype scale. As a first step, the most essential parameters must be accounted for using a proper dimensional analysis which also considers scale effects. It will result in dimensionless efficiency curves which allow prediction of prototype efficiencies, yet valid for steady flow only. To take into account the variability of annual inflow as well as dynamic effects like filling and emptying of a particular separator, the efficiency characteristics of the separator are combined with a quantity-quality simulation model. Such a numerical model is able to compute inflow and outflow hydrographs and pollutographs and to account for the catchment data at the given site. It allows the computation of annual pollutant loads as well as of the percentage of sewage sediment fed to the treatment plant, i.e. an annual separation efficiency.

scholarly journals RESEARCH Of) THE MODEL SHELTERING INVESTIGATION OF A HARBOR

1974 ◽  
Vol 1 (14) ◽  
pp. 124
Author(s):  
Ho-Shuong Hou
Keyword(s):  
Wave Height ◽  
Model Test ◽  
Wave Diffraction ◽  
Wave Pattern ◽  
Model Tests ◽  
Test Results ◽  
Wave Direction ◽  
Wave Condition ◽  
Wave Refraction ◽  
Sheltering Effect

The Model Sheltering Experiment deals with the planning arrangement of the proposed harbor and is done by the worst wave condition (with respect to wave direction, wave height, and wave period) which probably occurred on the proposed harbor. The objectives of this experiment are to get the wave pattern of the harbor basin and to understand the various phenomena of the wave refraction, diffraction, and reflection caused by model test due to different harbor arrangement, and to comprehend the sheltering effect of the outer breakwaters. From the analysis of these test results, harbor planning of the most effective arrangement - the most economic length of breakwaters and the most ideal width of harbor entrance could be selected. For the purpose of analyzing results of model tests; comparison of theoretical wave diffraction calculation is proposed.

Documentation of Operational Limits of Free-Fall Lifeboats by Combining Model Tests, Full-Scale Tests, and Computer Simulation

2009 ◽  
Author(s):  
Wojciech E. Kauczynski ◽  
Per Werenskiold ◽  
Frode Narten
Keyword(s):  
Wave Height ◽  
Model Test ◽  
Free Fall ◽  
Model Tests ◽  
Full Scale ◽  
Test Results ◽  
Extrapolation Methods ◽  
Basic Performance ◽  
Calm Water ◽  
Full Scale Tests

Historically, approval of lifeboats is based on a “calm water” philosophy through the SOLAS regulatory regime. In spring 2005 during offshore installation tests in calm water, unacceptable structural deflection of the roof for one type of free-fall lifeboat was revealed. Immediate actions were initiated by the Norwegian Oil Industry Association (OLF) and Statoil, including the goal of studying and documenting the main performance factors for free-fall lifeboats at up to a 100-year weather condition. In addition, OLF has request to develop relevant criteria for in depth classification of performance, and finally to upgrade urgently, when relevant, all free-fall lifeboats operating on the Norwegian continental shelf to the agreed standards. The basic performance criteria of free-fall lifeboat systems in emergency conditions are: structural strength, acceleration loads on passengers during water impact, boat forward speed immediately after water entry, and the manoeuvring away to a safe distance from the installation. Within the OLF-project, MARINTEK has performed an extensive model test program (over 25000 tests) with the 14 different types of free-fall lifeboats (launched by vertical drop or from a skid). Boat performances have been examined in different weather conditions, ranging from still water up to 11m wave height (regular waves and wind) or 7m (irregular significant wave height with corresponding wind). Calm water model test results have been compared to full-scale test results. In order to extend prognosis of the lifeboat performances up to 100-year storm condition (Hs = 15.7m), special extrapolation methods have been developed for studying the three basic performance areas, augmented by computer simulations applied for higher sea states. This paper presents example results and experiences gained from the model tests, full-scale tests and combined use of simulations and model test results. Experimental model test set-up and applied analysis and extrapolation methods are reviewed. Finally, the application of newly proposed performance and technical criteria is discussed.

Investigation on Reasons for Possible Difference Between VIM Response in the Field and in Model Tests

2016 ◽  
Author(s):  
Arjen Koop ◽  
Jaap de Wilde ◽  
André Luís Condino Fujarra ◽  
Oriol Rijken ◽  
Samuel Linder ◽  
...  
Keyword(s):  
Reynolds Number ◽  
Fatigue Damage ◽  
Model Test ◽  
Scale Effects ◽  
Model Tests ◽  
Full Scale ◽  
Strong Impact ◽  
Numerical Verification ◽  
Field Observations ◽  
Test Results

Floating offshore structures, such as production semi-submersibles and spars, can exhibit significant in-line and transverse oscillatory motions under current conditions. When caused by vortex shedding from the floater, such motions are generally called Vortex-Induced Motions (VIM). For semi-submersibles these motions could have a strong impact on the fatigue life of mooring and riser systems. Some field development studies indicate that the VIM induced fatigue damage for larger diameter Steel Catenary Risers (SCRs) can have a magnitude equal to or larger than the wave-induced fatigue damage. The VIM phenomenon for multi-column floaters is characterized by complex interactions between the flow and the motions of the floater. Presently, model tests are the preferred method to predict the VIM response of a multi-column floater. However, several studies indicate that the observed VIM response in the field is less than what is observed in model test campaigns: typical model test results are very conservative. Using such test results in the development of mooring and riser design can easily result in very conservative designs which can have a significant impact on mooring and riser cost, or even affect SCR selection and/or feasibility. The primary objective of the VIM JIP was to increase the physical insight into the VIM phenomenon. This knowledge is then used to address possible areas that could explain the differences between the results from model tests and field observations. To address these objectives, the JIP focused on model testing and CFD studies. A key segment of the JIP was the use of identical semi-submersible hull geometries for the numerical and experimental studies thereby facilitating the interpretation of the various response comparisons. The JIP identified that a CFD model, at model-scale Reynolds number, can reasonably well reproduce the VIM response observed in model tests. However, to have confidence in the CFD results extensive numerical verification studies have to be carried out. The effect of external damping was investigated in model tests and in CFD calculations. Both the numerical and experimental results show that external damping significantly reduces the VIM response. Comparisons between CFD results at model- and full-scale Reynolds number indicate that Froude scaling is applicable, with minor scale effects identified on the amplitudes of the VIM motions. Changing the mass ratio of the floater has a small influence on the VIM response. Experimentally it was found that VIM response under inline or transverse waves is slightly smaller than without the presence of waves and is wave heading and wave height dependent. The presence of waves does not explain the observed differences between model test results and field observations. The effect of unsteady current on the VIM response is minimal. Based on the results from the JIP it is concluded that increased external damping reduces the VIM response. The questions that remain are if the increased external damping is actually present in full-scale conditions and if the mooring and riser systems provide the required damping to reduce the VIM amplitudes.

scholarly journals WAVE RUN-UP IN FIELD MEASUREMENTS WITH NEWLY DEVELOPED INSTRUMENT

1976 ◽  
Vol 1 (15) ◽  
pp. 43 ◽  
Author(s):  
Heie F. Erchinger
Keyword(s):  
Scale Effects ◽  
Field Measurements ◽  
Storm Surges ◽  
Model Tests ◽  
Coastal Structures ◽  
Logarithmic Distribution ◽  
Run Up ◽  
The Waves ◽  
Natural Wind

The height of dikes and other coastal structures can only be calculated after determination of the wave run-up. Several formulas for the calculation of wave run-up are developed after model tests as a rule. But the influences of scale effects and natural wind conditions are practically unknown. To clear these questions further investigations and especially field measurements should be carried out. By measuring the markerline of floating trash on the slope of the seadikes the maximum wave run-up could be found out after four storm surges in 1967 and 1973- In two graphs it will be shown that on the tidal flats the run-up depends on the waterdepth. The run-up was higher than it could be expected after model tests of 1954. With a newly developed special echo sounder the run-up could be measured in January 1976. The waves and the run-up could be registrated synchronously during two severe storm surges. As shown in Fig. 9 it was found a logarithmic distribution of the wave height, wave period and the higher part of the wave run-up. The found wave run-up is considerably higher than estimated before. The measured 98 % run-up is found about twice the computed value. That is an interesting and important result of the first synchronous recording of wave run-up on sea dikes.

IMPROVE THE INTERETATION OF STUDY SUBJECTS PANCASILA AND CITIZENSHIP EDUCATION BY APPLYING KONSTEXTUAL LEARNING MODEL BERBASIS A TASK IN CLASS INFORMATICS XI SMK BINA ECLECTUS ACADEMIC YEAR 2015/2016

EDUKASI ◽  
2016 ◽  
Vol 13 (2) ◽  
Author(s):  
Hasanudin S. Usman
Keyword(s):  
Teaching And Learning ◽  
Learning Model ◽  
Positive Influence ◽  
Motivation To Learn ◽  
Test Results ◽  
Applied Learning ◽  
Know How ◽  
Design Activities ◽  
The Subject ◽  
Academic Year

The purpose of this research is to know how to incerease the students’ learning achievement that has been applied learning contextual task-based learning model and to know the influence of contextual learning in  the task-based teaching model to improve achievemen and motivation to learn the material pe civis lesson.   This research is an action research by theree rounds. Each round consists of four phases. Design activities are observation, and revesion. The subject of the research is XI grade students of Bina Informatika Ternate accademic year 2015/2016. Data obtained in the form of a formative test results, observation sheet teaching and learning activities. The results of the research showed that students’ achivement increased from round I to III that the round 1, (70.00 % ), (92,50 %)  3 cycles, conclusions of this research is the method of cooperatif learning can be a positive influence on students motivation and achievement in material udaya politics in Indonesia. It means that this model can be used as one of the alternative learning for Pkn.            Kata  kunci: PKn, cooperative learning method

Nonlinear Trend Analysis of Mill Fan System Vibrations for Predictive Maintenance and Diagnostics

2012 ◽  
Vol 58 (4) ◽  
pp. 351-356
Author(s):  
Mincho B. Hadjiski ◽  
Lyubka A. Doukovska ◽  
Stefan L. Kojnov
Keyword(s):  
Power Plant ◽  
Trend Analysis ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Thermal Power ◽  
Balkan Peninsula ◽  
Predictive Maintenance ◽  
Nonlinear Trend ◽  
The Subject ◽  
The Given

Abstract Present paper considers nonlinear trend analysis for diagnostics and predictive maintenance. The subject is a device from Maritsa East 2 thermal power plant a mill fan. The choice of the given power plant is not occasional. This is the largest thermal power plant on the Balkan Peninsula. Mill fans are main part of the fuel preparation in the coal fired power plants. The possibility to predict eventual damages or wear out without switching off the device is significant for providing faultless and reliable work avoiding the losses caused by planned maintenance. This paper addresses the needs of the Maritsa East 2 Complex aiming to improve the ecological parameters of the electro energy production process.

Mobile-Friendly Dashboards to Display Associations Between Cited-by and Similar Journals on Mobile Health Research: A Bibliometric Study (Preprint)

2018 ◽  
Author(s):  
Tsair-Wei Chien ◽  
Hsien-Yi Wang ◽  
Yang Shao ◽  
Willy Chou
Keyword(s):  
Social Network ◽  
Mobile Health ◽  
Health Research ◽  
Similarity Criteria ◽  
Network Density ◽  
Deep Insight ◽  
Density Indices ◽  
The Subject ◽  
The Given ◽  
Insight Into

BACKGROUND Researchers often spend a great deal of time and effort retrieving related journals for their studies and submissions. Authors often designate one article and then retrieve other articles that are related to the given one using PubMed’s service for finding cited-by or similar articles. However, to date, none present the association between cited-by and similar journals related to a given journal. Authors need one effective and efficient way to find related journals on the topic of mobile health research. OBJECTIVE This study aims (1) to show the related journals for a given journal by both cited-by and similarity criteria; (2) to present the association between cited-by and similarity journals related to a given journal; (3) to inspect the patterns of network density indices among clusters classified by social network analysis (SNA); (4) to investigate the feature of Kendall's coefficient(W) of concordance. METHODS We obtained 676 abstracts since 2013 from Medline based on the keywords of ("JMIR mHealth and uHealth"[Journal]) on June 30, 2018, and plotted the clusters of related journals on Google Maps by using MS Excel modules. The features of network density indices were examined. The Kendall coefficient (W) was used to assess the concordance of clusters across indices. RESULTS This study found that (1) the journals related to JMIR mHealth and uHealth are easily presented on dashboards; (2) a mild association(=0.14) exists between cited-by and similar journals related to JMIR mHealth and uHealth; (3) the median Impact Factor were 3.37 and 2.183 based on the representatives of top ten clusters grouped by the cited-by and similar journals, respectively; (4) all Kendall’s coefficients(i.e., 0.82, 0.89, 0.92, and 0.75) for the four sets of density centrality have a statistically significant concordance (p < 0.05). CONCLUSIONS SNA provides deep insight into the relationships of related journals to a given journal. The results of this research can provide readers with a knowledge and concept diagram to use with future submissions to a given journal in the subject category of Mobile Health Research. CLINICALTRIAL Not available

Proses Berpikir Kreatif Siswa Tipe Linguistik dalamPemecahan Masalah Biologi

2014 ◽  
Vol 2 (2) ◽  
Author(s):  
Imelda Aisah Sarip ◽  
Kamid Kamid ◽  
Bambang Hariyadi
Keyword(s):  
Problem Solving ◽  
Data Collection ◽  
Creative Thinking ◽  
Research Data ◽  
Think Aloud ◽  
The Subject ◽  
Thinking Process ◽  
Problem Solving Process ◽  
The Given

The aim of this research is to describe creative thinking process of linguistic type student in biology problem solving. This research is conducted to linguistic intelligence type of subject at SMPN 6 Kota Jambi. SL the subject was selected based on the aim of the research. Data collection is conducted by interview and a modified think aloud method. Data is analyzed based on creative thinking process purposed by Polya.The result of this research shows that SL could find and arrange the given problems and collect data correctly and appropriately. The problem solving steps is done systematically to the end of problem solving process. The last steps problem solving, SL does checking while doing scratching to make sure that the written answers meet her need.

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