Heave and Pitch Response of an Offshore Platform With Air Cushion Support in Shallow Water

2004 ◽  
Author(s):  
K. P. Thiagarajan ◽  
M. T. Morris-Thomas ◽  
A. Spargo
Keyword(s):  
Linear Wave ◽  
Test Results ◽  
Regular Waves ◽  
Long Wavelength ◽  
Air Cushion ◽  
Decay Tests ◽  
Heave Motion ◽  
The University ◽  
Scaled Models ◽  
Water Depths

Model tests were conducted on two 1:100 scaled models of a typical concrete gravity substructure at the University of Western Australia. The two models had dimensions 0.5m length × 0.5m width with the first model being a sealed closed bottom box of height 0.1m and the second model being an open bottom box with skirt length of 0.1m. The open bottom model had the capacity to hold an air cushion with dimensions 0.49m width × 0.49m length × 0.08m height. Each model was floated at a constant draft of 0.1m and tested in water depths ranging between 0.03m (shallow) and 0.8m (deep). The environment comprised of regular waves with periods ranging between 0.6s and 3.5s and amplitude of 0.08m–0.02m. To quantify the dynamic response the heave and pitch motion of each model were measured. The model test results were compared with a theoretical solution based on long wavelength, linear wave assumptions applied to a box shaped floating vessel without an internal free surface. Results show that experimental trends compare reasonably well with analytical solution. Added mass values were predicted from heave and pitch decay tests. The results show that introducing air cushion support into a CGS increases the pitch response, while having little effect of the heave motion. The theory is also used to delineate regions of safe and unsafe tow-out operations of the air cushion structure.

scholarly journals Experimental investigations on tension based tension leg platform (TBTLP)

2014 ◽  
Vol 11 (2) ◽  
pp. 105-116
Author(s):  
D. S. Bhaskara Rao ◽  
R. Panneer Selvam ◽  
Nagan Srinivasan
Keyword(s):  
Degrees Of Freedom ◽  
Experimental Investigations ◽  
Regular Waves ◽  
Tension Leg Platform ◽  
Scaled Model ◽  
Deep Waters ◽  
Offshore Industry ◽  
Motion Characteristics ◽  
Heave Motion ◽  
Water Depths

Tension Leg Platforms (TLPs) are one of the reliable structures for offshore industry in deep waters because of its motion characteristics in heave, roll and pitch degrees of freedom. Heave motion is very important in offshore facilities and have to kept as minimum as possible. As the water depth increases TLPs suffers from some limitations and hence has to be modified to cater to deeper waters. One such concept proposed is Tension Based Tension Leg Platform (TBTLP). In this paper, experimental investigations carried out on a scaled model of a Tension Based Tension Leg Platform in regular waves are reported. This is the first ever experiments that was carried out on a scaled model of the new concept. To investigate the effect of Tension Base, experiments were also conducted on the TLP (without Tension Base) in two different water depths. RAOs have been compared for surge and heave dof of TLP and TBTLP. Numerical modeling of the TLP and TBTLP responses using ANSYS AQWA software are included as well for comparisons.DOI: http://dx.doi.org/10.3329/jname.v11i2.17341

Faktor – Faktor Yang Mempengaruhi Minat Berwirausaha Mahasiswa Program Studi Manajemen Fakultas Ekonomi Universitas Flores

Analisis ◽  
2020 ◽  
Vol 19 (1) ◽  
pp. 76-84
Author(s):  
Nasarius Aban ◽  
Gabriel Tanusi
Keyword(s):  
Emotional Intelligence ◽  
Regression Analysis ◽  
Family Environment ◽  
Linear Regression Analysis ◽  
Simple Random Sampling ◽  
Coefficient Of Determination ◽  
Test Results ◽  
Study Program ◽  
Management Study ◽  
The University

This study aims to determine the effect of emotional intelligence, independent attitude and family environment on the interest in entrepreneurship at the University of Flores Management Faculty of Economics. This research is an associative research. The population in this study were students of the Management Study Program of the Faculty of Economics of the University of Flores in the class of 2015-2016 who had passed the entrepreneurship courses of 170 people. Samples taken in this study were 105 respondents, with sampling techniques using simple random sampling. Data collection using questionnaires and interviews, while data analysis was performed using multiple linear regression analysis. The results of multiple regression analysis are Y = 1.060 + 0.594X1 + 0.114X2 + 0.421X3 + e. The coefficient of determination R2 for the variables X1, X2, X3 is 0.675, which means that entrepreneurial interest can be influenced by emotional intelligence, independent attitude and family environment by 67.50% and the remaining 32.50% is influenced by other factors including factors of education, skills, motivation and others. F test results show the value of Fcount> Ftable (28.442> 2.69) with a significant level of 0.000 <0.05 meaning that there is a positive and significant influence between emotional intelligence, independent attitude and family environment together on the entrepreneurial interest of the Faculty of Management Study Program Students The economy. Partial test results (t) show 1) Emotional intelligence factors have a positive and significant effect on entrepreneurial interest 2) Family environment factors have a positive and significant effect on entrepreneurial interest 3) Independent attitude factor has no positive and significant effect on entrepreneurial interest.

Promoting positive washforward through personalised test feedback and other benefits: Piloting a computer-based testing system

2020 ◽  
Vol 10 (1) ◽  
pp. 235-244
Author(s):  
Elena A. M. Gandini ◽  
Tania Horák
Keyword(s):  
Foreign Language ◽  
Testing System ◽  
Test Results ◽  
Test Feedback ◽  
Teachers And Students ◽  
Computer Based ◽  
Computer Based Testing ◽  
The University ◽  
Future Learning ◽  
Personalised Feedback

AbstractThis contribution reports on the developing and piloting of a computer-based version of the test of English as a foreign language produced by the University of Central Lancashire (UCLan), where it is currently used for the admission of international students and the subsequent evaluation of their language progress. Among other benefits, computer-based testing allows for better and individualised feedback to both teachers and students, and it can provide a more authentic test experience in light of the current digital shift that UK universities are undergoing. In particular, the qualitative improvement in the feedback available for test-takers and teachers was for us a crucial factor. Providing students with personalised feedback, that is, directly linked to their performance, has positive washforward, because it means we can guide their future learning, highlighting the areas they need to work on to improve their language skills and giving them suggestions on how to succeed in academia. Furthermore, explaining the meaning of test results in detail improves transparency and ultimately washback, as teachers can use the more accessible marking criteria, together with information on how their students performed, to review plans and schemes of work for subsequent courses.

Development and Verification of Modeling Practice for CFD Decay Calculations to Obtain Roll Damping of FPSO

2021 ◽  
Author(s):  
Arjen Koop ◽  
Pierre Crepier ◽  
Sebastien Loubeyre ◽  
Corentin Dobral ◽  
Kai Yu ◽  
...  
Keyword(s):  
Model Test ◽  
Test Results ◽  
Cfd Modelling ◽  
Roll Damping ◽  
Natural Period ◽  
Computational Mesh ◽  
Safety Studies ◽  
Offshore Industry ◽  
Decay Tests ◽  
Set Up

Abstract Estimates for roll damping are important input parameters for simulation studies on vessels operating at sea, e.g. FPSO mooring in waves, wind and current, workability and operability investigations, Dynamic Position studies, ship-to-ship operations and safety studies of vessels. To accurately predict the motions of vessels this quantity should be determined with confidence in the values. Traditionally, model experiments in water basins using so-called decay tests are carried out to determine the roll damping. With recent advancements in CFD modelling, the offshore industry has started using CFD as an alternative tool to compute the roll damping of FPSO’s. In order to help adopt CFD as a widely accepted tool, there is a need to develop confidence in CFD predictions. Therefore, a practical CFD modelling practice is developed within the Reproducible CFD JIP for roll decay CFD simulations. The Modelling Practice describes the geometry modelling, computational mesh, model set-up and post-processing for these type of CFD calculations. This modelling practice is verified and validated by three independent verifiers against available model test data. This paper provides an overview of the developed modelling practice and the calculated CFD results from the verifiers. The CFD modelling practice is benchmarked against available model test results for a tanker-shaped FPSO. By following this modelling practice, the CFD predictions for the equivalent linear damping coefficient and natural period of the roll motions are within 10% for all verifiers and within 10% from the model test results. Therefore, we conclude that when following the developed modelling practice for roll decay simulations, reliable, accurate and reproducible results can be obtained for the roll damping of tanker-shaped FPSOs.

Global Hydroelastic Analysis of Pontoon-Type VLFS

2009 ◽  
Author(s):  
L. L. Jiao ◽  
M. Greco ◽  
O. M. Faltinsen
Keyword(s):  
Numerical Solutions ◽  
Parameter Analysis ◽  
Local Analysis ◽  
Two Dimensional ◽  
Numerical Wave Tank ◽  
Regular Waves ◽  
Hydroelastic Analysis ◽  
Air Cushion ◽  
Numerical Wave ◽  
Hydroelastic Response

A two-dimensional composite strategy given by Greco et al. [1] is applied to couple a linear global solution with a nonlinear local analysis. Globally a linear hydroelastic analysis is performed by an accurate Beam-On-Elastic-Foundation (BOEF) method. A parameter analysis of hydroelastic response of the structure is also carried out. Locally, a two-dimensional fully-nonlinear numerical wave tank (NWT) in combination with a Boundary Element Method (BEM) is developed to estimate the interaction between regular waves and the structure restrained from rigid and elastic motions. The effect of air cushion is considered. Present results are compared with experimental data and other numerical solutions.

Automated Approaches Determine Solids Content in Drilling and Completions Fluids

2021 ◽  
Vol 73 (11) ◽  
pp. 51-52
Author(s):  
Chris Carpenter
Keyword(s):  
Elevated Temperatures ◽  
Drilling Fluid ◽  
Technical Conference ◽  
Drilling Fluids ◽  
Test Results ◽  
University Of Texas ◽  
Safety Issues ◽  
Recommended Practices ◽  
Solids Content ◽  
The University

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201368, “Automated Solids-Content Determination in Drilling and Completions Fluids,” by Sercan Gul, SPE, Ali Karimi Vajargah, and Eric van Oort, SPE, The University of Texas at Austin, et al., prepared for the 2020 SPE Annual Technical Conference and Exhibition, originally scheduled to be held in Denver, 5–7 October. The paper has not been peer reviewed. Monitoring of low- and high-gravity-solids (LGS and HGS) content and maintaining these at ideal levels is essential for optimal drilling fluid performance, efficient hole cleaning and equivalent-circulating-density management, and prevention of failures of surface and downhole equipment during drilling. LGS and HGS monitoring in the field is currently accomplished using the API retort-kit measurement, which has certain drawbacks and is difficult to automate. In the complete paper, two new approaches are investigated to automate the LGS and HGS content measurements of drilling fluids, which potentially can replace the retort test. Introduction The conventional way to characterize LGS and HGS in the field is by using a retort-kit measurement specified in API Recommended Practices 13B-1 and 13B-2. The longevity of these tests is testament to the effectiveness of the API standards and the tests themselves in providing useful and practical field guidance. Despite their evident success, however, various downsides exist in current solids-content-testing methods. Retort-kit measurements present the following issues: - Difficulty in obtaining accurate and repeatable test results - Safety issues associated with laboratory testing at elevated temperatures (over 930°F) - Interpretive bias issues associated with test results, including the potential for deliberate manipulation of these results - Difficulty in automating the retort test for improved efficiency and safety The authors’ opinion is that automating antiquated API test protocols is not a useful practice. They write that a clean-slate approach would be better, in which a determination is made whether solids-content information can be provided in a novel and meaningful way using methods that deviate from standard API recommended practices. In the complete paper, the authors investigate a machine-learning (ML) and data-analytics method for this purpose in combination with a novel inline X-ray fluorescence (XRF) measurement method.

scholarly journals Home Care in Germany: Philosophy of Treatment, Results of Intensive Care

1977 ◽  
Author(s):  
H.H. Brackmann ◽  
P. Hoffmann ◽  
F. Etzel ◽  
Eqli H. Hildenbrand
Keyword(s):  
Hemophilia A ◽  
Time Lag ◽  
Test Results ◽  
Treatment Results ◽  
Pathophysiological Process ◽  
General Test ◽  
New Ideas ◽  
General Goal ◽  
The University ◽  
And Training

In the FRG the work of several centers is concerned with introducing a program of self-treatment for hemophi1iacso The general goal of a self-treatment-program is: avoidance of a time lag due to long distances and the expansion of personal freedom and life style possibilities.In respect to the dosage and treatment duration various opinions exist, some of them differing quite noticably from ours. Our conception about the therapy, existing since the beginning of our program (June 1971), is based on an intensive cooperation with the department of orthopedics at the university. Through our teamwork the following results were achieved:- the evaluation of 17.196 acute bleedings registered 93% joint and muscle bleedings- 98% of the patients over 11 years of age with severe and semi-severe hemophilia A or B revealed at least one, in several cases more, arthropathic changes- the pathophysiological process of a joint bleeding leads to an important electromyographic test as well as to new ideas about biomechanic.Based on the general test results a specific dosage plan for each patient resulted, which, together with the orthopedic findings took into consideration the attained biological recovery. Since our goal is the strenghtening and training of muscle in general, every patient receives a specially adopted training program, which largely excludes bleeding. Our results have lead to a 90% improvement of the original orthopedic finding.

De Moeilijkheidsgraad Van Tekstbegripvragen In Nederlands En Engels

1992 ◽  
Vol 43 ◽  
pp. 97-104
Author(s):  
P. Edelenbos ◽  
Pieter Loonen ◽  
Herman Wekker
Keyword(s):  
Strong Correlation ◽  
Text Comprehension ◽  
Test Score ◽  
Test Results ◽  
Single Item ◽  
Final Exams ◽  
General Test ◽  
Factual Content ◽  
Level Of Difficulty ◽  
The University

The final exams for English in Dutch secondary schools contain a multiple choice component for text comprehension. The questions in this component are mainly about factual content but progressively also about communicative aspects such as opinions and style. It is usually assumed that the latter add to the level of difficulty of the test in general. But is this really the case? In a (limited) project caried out by the University of Groningen this assumption has been tested in six pre-final forms at three grammartype schools, by setting the same test in Dutch and in English within a six-week interval. At the same time the influence of vocabulary command was mapped out against the overall test results. The communicative questions did not turn out to be more difficult in English than in Dutch and there appeared to be a strong correlation between the overall (not: single item) vocabulary command and general test score. The average test results were considerably higher (4.0) for the Dutch test than for the equivalent English one.

Minimizing Sampling Loss in Trace Gas Emission Measurements for Aircraft Engines by Using a Chemical Quick-Quench Probe

2010 ◽  
Author(s):  
Elena de la Rosa Blanco ◽  
Jay Peck ◽  
Richard C. Miake-Lye ◽  
Frank B. Hills ◽  
Ezra C. Wood ◽  
...  
Keyword(s):  
Chemical Reactions ◽  
Aircraft Engine ◽  
Trace Gas ◽  
Test Results ◽  
University Of Tennessee ◽  
Quench Probe ◽  
Gas Sampling ◽  
Helium Dilution ◽  
The University ◽  
Engine Power

This paper describes the development and testing of a gas sampling probe that quenches chemical reactions by using supersonic expansion and helium dilution. Gas sampling probes are required for accurate measurement of exhaust emissions species, which is critical to determine the performance of an aircraft engine. The probe was designed through rounds of computational modeling and laboratory testing, and was subsequently manufactured and then tested at the University of Tennessee Space Institute (UTSI) behind a General Electric J85 turbojet engine at different power settings: idle, maximum military and afterburning. The experimental test results demonstrated that the Chemical Quick-Quench (CQQ) probe suppressed the oxidation of carbon monoxide (CO) inside the probe system and preserved more CO at afterburning conditions. In addition, the CQQ probe prevented hydrocarbons from being partially-oxidized to form CO at idle powers, and measured higher hydrocarbons and lower CO emission compared to a conventional probe at that low power condition. The CQQ probe also suppressed nitrogen dioxide (NO2) to nitric oxide (NO) conversion through all engine power settings. These data strongly support the conclusion that the CQQ probe is able to quench unwanted chemical reactions inside the probe for all engine power levels.

Study of the Wave Drift Damping for a Very Large Crude Carrier

2007 ◽  
Author(s):  
Joel S. Sales ◽  
Vinicius L. F. Matos ◽  
Andre R. da Silva ◽  
Ge´rson B. Matter ◽  
Sergio H. Sphaier
Keyword(s):  
Linear Part ◽  
Regular Waves ◽  
Damping Coefficients ◽  
Pull Out ◽  
Wave Drift ◽  
Decay Test ◽  
Wave Drift Damping ◽  
Linear Damping ◽  
The Mean ◽  
Decay Tests

Pull-out test and decay tests in still water and in waves for the surge motion of a VLCC in ballast condition are carried out at LabOceano. The pull-out test associated with the mean drift displacement in regular waves is used to determine mean drift force. From the decay tests the damping coefficients are adjusted using the Froude energy method and the procedure based on the logarithm decrement. For the decay test in waves, the response is subdivided in the mean drift contribution, the regular wave response and the transient response. The wave drift damping is considered as an increase on the linear damping in still water. So, we introduce an additional damping to the linear part of the damping coefficient in still water and simulate the decay test in waves. Comparing the results from the simulation with the experiments the wave drift damping contribution is adjusted. Finally, the mean drift results are compared with the results obtained with the potential theory. The wave drift damping coefficients obtained from the experiments are compared with coefficients obtained with a formulation proposed in the literature.

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