Scale model test results of several STOVL ventral nozzle concepts

Author(s):  
B. MEYER ◽  
R. RE ◽  
J. YETTER
Keyword(s):  
1994 ◽  
Vol 116 (1) ◽  
pp. 75-81 ◽  
Author(s):  
A. M. Birk ◽  
D. VanDam

Sea Trials have recently been underway for Canada’s new City Class Patrol Frigate (CPF). These trials provided the first opportunity to measure the performance of the new DRES Ball Infrared Signature Suppression (IRSS) system installed on a ship. Prior to these trials 1/4-scale hot flow model test and computer simulation performance results were available. The CPF DRES Ball IRSS systems are installed on the exhaust uptakes of the GE LM2500 main gas turbines. The DRES Ball provides both metal surface cooling for all view angles and plume cooling. The DRES Ball significantly reduces the IR signature of the LM2500 exhaust. This paper presents a comparison between the 1/4-scale hot flow model test results with the full-scale sea trial results. Performance variables included in the comparison are: metal surface temperatures, back pressure, plume temperature distribution, and surface static pressures. Because of the confidential nature of the DRES Ball system performance, all classified data have been nondimensionalized so that only relative comparisons can be made between the full-scale and 1/4-scale data. The results show that the full-scale system performs better than the 1/4-scale model because of Reynolds number effects. The plume temperature, surface temperatures, and back pressure were all lower (better) than in the 1/4-scale model tests. One of the original concerns with the installation was that relative wind would degrade the performance of the DRES Ball onboard a ship. The wind effect was found to be benign during the trials.


Author(s):  
A. M. Birk ◽  
D. Vandam

Sea Trials have recently been underway for Canada’s new City Class Patrol Frigate (CPF). These trials provided the first opportunity to measure the performance of the new DRES Ball Infra-red Signature Suppression (IRSS) system installed on a ship. Prior to these trials 1/4 scale hot flow model test and computer simulation performance results were available. The CPF DRES Ball IRSS systems are installed on the exhaust uptakes of the GE LM2500 main gas turbines. The DRES Ball provides both metal surface cooling for all view angles and plume cooling. The DRES Ball significantly reduces the IR signature of the LM2500 exhaust. This paper presents a comparison between the 1/4 scale hot flow model test results with the full scale sea trial results. Performance variables included in the comparison are; metal surface temperatures, back pressure, plume temperature distribution, and surface static pressures. Because of the confidential nature of the DRES Ball system performance, all classified data has been nondimensionalized so that only relative comparisons can be made between the full scale and 1/4 scale data. The results show that the full scale system performs better than the 1/4 scale model because of Reynolds number effects. The plume temperature, surface temperatures and back pressure were all lower (better) than in the 1/4 scale model tests. One of the original concerns with the installation was that relative wind would degrade the performance of the DRES Ball onboard a ship. The wind effect was found to be benign during the trials.


Author(s):  
Wei Xiaobo ◽  
Huilong Ren ◽  
Yanlong Sun ◽  
Di Wang ◽  
Zhen Yu Wang

Trimaran, as a high performance ship, its special ship form is different from regular monohull ship. The particular characteristics of longitudinal and transverse wave loads are concerned greatly by ship structure designers. Theoretical methods for forecasting the wave loads of trimaran are under developing. And the relative comprehensive model test study of trimaran’s wave loads is rare in the publication. In this paper, the trimaran model test had been carried out in the tank. According to similarity theory and simulation of stiffness, a scale model of trimaran with measurement system had been manufactured. Then the segmented model had navigated in regular waves of different sea conditions. Through analysis of the experimental data, the wave loads characteristics of this trimaran are presented. A comparison of test results and theoretical values is also made to show the similarities and differences. This study can provide some useful information for further design of high-speed trimaran in the point of wave loads, which maybe a reference for research of trimaran.


1986 ◽  
Vol 108 (2) ◽  
pp. 168-172 ◽  
Author(s):  
A. Freitas ◽  
R. S. Nishizaki

Alternative bow forms have been investigated for the “M. V. Arctic” in a test program sponsored by the German Ministry for Research and Technology and the Transportation Development Centre of Transport Canada. The “M. V. Arctic” is a Canadian Arctic Class 2 bulk carrier of 28000 dwt which operates between the Northwest Territories and Europe during the summer and fall months. The tests were conducted at the Hamburg Ship Model Basin using a 1/30th scale model fitted with three different forebody forms. These included the Thyssen/Waas design, a new design by Melville Shipping Ltd., Calgary, and the existing bow form. The tests were performed in ice, still water and irregular seaway. The Thyssen/Waas icebreaker system includes a novel bow form and employs an unconventional icebreaking technique. The system has been successfully tested in model and demonstrated in full scale with the modified icebreaker “Max Waldeck”. The Melville design uses a conventional form incorporating the latest technology. This paper describes the model tests and discusses the relative performance as indicated by the test results. The investigation has shown the potential for the use of the Thyssen/Waas bow form on icebreaking cargoships such as the “M.V. Arctic”.


1990 ◽  
Author(s):  
T. FLUGSTAD ◽  
B. ROMINE ◽  
R. WHITTAKER

2021 ◽  
Vol 2083 (4) ◽  
pp. 042051
Author(s):  
Xianggang Wang ◽  
Yongli Shen ◽  
Yongcheng Yang ◽  
Xinxin Zhou ◽  
Gangnian Xu ◽  
...  

Abstract Dongming Yellow River Highway Bridge is an important super large bridge across the Yellow River on national highway 106. In order to effectively improve the cracking and deflection of the bridge, the cable-stayed system is used to reinforce the main girder of the project. In order to analyze the stress state of joist, bracket and box girder, the static loading of cable is carried out through scale model test to study the mechanical properties of concrete box girder segment, joist and bracket, verify the reliability of bracket and concrete box girder anchorage, and optimize the reinforcement method of cable-stayed system according to the test results.


Author(s):  
X.X. Cheng ◽  
J. Dong ◽  
Y. Peng ◽  
L. Zhao ◽  
Y.J. Ge

Full-scale/model test comparison studies to validate the traditional ABL wind tunnel simulation technique are reviewed. According to the literature review, notable discrepancies between full-scale measurement results and model test results were observed by most performed comparison studies, but the causes of the observed discrepancies were not revealed in a scientific way by those studies. In this regard, a new research scheme for future full-scale/model test comparison studies is proposed in this article, which utilizes the multiple-fan actively controlled wind tunnel simulation technique. With the new research scheme, future full-scale/model test comparison studies are expected to reasonably disclose the main problems with the traditional ABL wind tunnel simulation technique, and the technique can be improved correspondingly.


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