Experimental study on squeal noise generated on curved sections for railway lines with using scale model tests

2018 ◽  
Vol 2018 (0) ◽  
pp. G1001005
Author(s):  
Tsugutoshi KAWAGUCHI ◽  
Takeshi SUEKI ◽  
Toshiki KITAGAWA ◽  
Shinji YAMADA
Author(s):  
Saeid Kazemi ◽  
Atilla Incecik

An experimental study for predicting the air gap and potential deck impact of a floating offshore structure is the main topic of this research. Numerical modeling for air gap prediction is particularly complicated in the case of floating offshore structures because of their large volume, and the resulting effects of wave diffraction and radiation. Therefore, for new floating platforms, the model tests are often performed as part of their design process. This paper summarizes physical model tests conducted on a semi-submersible model, representing a 1-to-100 scale model of a GVA4000 class, “IRAN-ALBORZ”, the largest semi-submersible platform in the Caspian Sea, under construction in North of Iran, to evaluate the platform’s air gap at different locations of its deck and also measure the impact forces in case of having negative air gap. The model was tested in regular waves in the wave tank of Newcastle University. The paper discusses the experimental setup, test conditions, and the resulting measurements of the air gap and the wave impact forces by using eight wave probes and three load cells located at different points of the lower deck of the platform.


Author(s):  
Yun Su Han ◽  
Jeong Woo Hong ◽  
Min Han Oh ◽  
Jong Jin Jung

The purpose of a gravity anchor is to moor the installation barge affected by the environmental condition during installation at the offshore site. It is important to obtain the sufficient holding capacity to prevent the anchor from dragging. There are several methods to enhance the holding capacity such as increasing its self-weight or attaching the shear key at the bottom of the gravity anchor. However, increasing the self-weight of gravity anchor is a constrained approach due to the limitation of handling equipment capacity. Therefore, it is necessary that the shear key design should be optimized to maximize the holding capacity under limited handling equipment. In this paper, reduced scale model tests simulating rock condition mixed by sand, cement, and water are performed. The actual offshore mooring condition is simulated by using towing carriage. Five types of gravity anchor models which have different shear keys are assessed to examine what type of the shear key is the optimum design. The optimum shape and the number of shear keys for maximizing the holding capacity are assessed through this study. The results of this study can be utilized to design the shear key of gravity anchor.


2020 ◽  
Vol 17 (6) ◽  
pp. 172988142097677
Author(s):  
Zhilin Liu ◽  
Linhe Zheng ◽  
Guosheng Li ◽  
Shouzheng Yuan ◽  
Songbai Yang

In recent years, the trimaran as a novel ship has been greatly developed. The subsequent large vertical motion needs to be studied and resolved. In this article, an experimental study for a trimaran vertical stabilization control is carried out. Three modes including the bare trimaran (the trimaran without appendages, the trimaran with fixed appendages, and the trimaran with controlled appendages) are performed through model tests in a towing tank. The model tests are performed in regular waves. The range of wave period is 2.0–4.0 s, and the speed of the carriage is 2.93 and 6.51 m/s. The results of the three modes show the fixed appendages and the actively controlled appendages are all effective for the vertical motion reduction of the trimaran. Moreover, the controlled appendages are more effective for the vertical stability performance of the trimaran.


2014 ◽  
Vol 66 (2) ◽  
Author(s):  
Mohammadreza Fathi Kazerooni ◽  
Mohammad Saeed Seif

One of the phenomena restricting the tanker navigation in shallow waters is reduction of under keel clearance in the terms of sinkage and dynamic trim that is called squatting. According to the complexity of flow around ship hull, one of the best methods to predict the ship squat is experimental approach based on model tests in the towing tank. In this study model tests for tanker ship model had been held in the towing tank and squat of the model are measured and analyzed. Based on experimental results suitable formulae for prediction of these types of ship squat in fairways are obtained.


Author(s):  
Andrew Cornett

Many deck-on-pile structures are located in shallow water depths at elevations low enough to be inundated by large waves during intense storms or tsunami. Many researchers have studied wave-in-deck loads over the past decade using a variety of theoretical, experimental, and numerical methods. Wave-in-deck loads on various pile supported coastal structures such as jetties, piers, wharves and bridges have been studied by Tirindelli et al. (2003), Cuomo et al. (2007, 2009), Murali et al. (2009), and Meng et al. (2010). All these authors analyzed data from scale model tests to investigate the pressures and loads on beam and deck elements subject to wave impact under various conditions. Wavein- deck loads on fixed offshore structures have been studied by Murray et al. (1997), Finnigan et al. (1997), Bea et al. (1999, 2001), Baarholm et al. (2004, 2009), and Raaij et al. (2007). These authors have studied both simplified and realistic deck structures using a mixture of theoretical analysis and model tests. Other researchers, including Kendon et al. (2010), Schellin et al. (2009), Lande et al. (2011) and Wemmenhove et al. (2011) have demonstrated that various CFD methods can be used to simulate the interaction of extreme waves with both simple and more realistic deck structures, and predict wave-in-deck pressures and loads.


1989 ◽  
Author(s):  
R. DE GAAIJ ◽  
E. VAN RIETBERGEN ◽  
M. SLEGERS

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