Controllable Pitch Propellers With Gas Turbine Prime Movers

1973 ◽  
Author(s):  
D. E. Ridley ◽  
J. A. Norton
Keyword(s):  
Gas Turbine ◽  
Ship Design ◽  
Full Scale ◽  
Design Phase ◽  
Transient Performance ◽  
Prime Movers ◽  
Scale Data

The paper is concerned with the transient performance of gas turbine/controllable pitch propeller ships propulsion plants in the decelerating mode with headway on the vessel. Conventional propeller coefficients are examined, and their deficiencies for this purpose noted, particularly with regard to preliminary predictions of performance in the initial ship design phase. A tentative set of revised coefficients is proposed, and the predictions compared to two sets of full-scale data.

scholarly journals THE RESISTANCE ASPECT OF FISHING BOAT SKIPJACK POLE AND LINE

2021 ◽  
Vol 4 ◽  
pp. 1-7
Author(s):  
Wolter R Hetharia ◽  
Eliza R De Fretes ◽  
Reico H Siahainenia
Keyword(s):  
Model Test ◽  
Ship Design ◽  
Full Scale ◽  
Suitable Method ◽  
Design Phase ◽  
Towing Tank ◽  
Model Scale ◽  
Fishing Boat ◽  
Fishing Vessels ◽  
The Difference

The operation of fishing vessels skipjack pole and line contributes in catching tuna and skipjack fishes particularly in Indonesian waters. A previous study conducted by the authors found that there was no suitable method provided for the resistance computation atearly ship design phase. Besides, there was aninitial trim existed on the vessel during the operation which contributes for the resistance. The purpose of the study is to find the difference of resistance between the model test and the existing methods. The study was executed also to find the effect of initial trim of the vessel. The study began with collecting the database of a parent ship then to develop and transform into a model-scale for testing purpose in the towing tank. The results of model test were converted to the full-scale vessel. The resistance of full-scale vessel was computed based on the Holtrop and Guldhammer methods. The result of full-of resistance obtained from the model test and the methods were collected, evaluated and compared. The results showed the difference of the resistance for all methods. The result of model test is greater 21 % than that of Holtrop method at the service speed of 10 knots. Meanwhile, the result of model test is lower 14 % than that of Gulhammer method at the same speed. In addition, at the speed of 10 knots the initial trim of 0.5O increase 5 % ofthe resistance, the initial trim of 1O increase 10 % of resistance and the initial trim of 2O increase 16 % of resistance compared to the vesselwithout initial trim. In conclusion, the existing resistance methods are not suitable to be applied for skipjack pole and line fishing vessels. In addition, the initial trim contributes to increase the resistance and should be avoided during the vessel operation.

Benchmarking of Truss Spar Vortex Induced Motions Derived From CFD With Experiments

2005 ◽  
Author(s):  
John Halkyard ◽  
Senu Sirnivas ◽  
Samuel Holmes ◽  
Yiannis Constantinides ◽  
Owen H. Oakley ◽  
...  
Keyword(s):  
Scale Up ◽  
Vertical Cylinder ◽  
Reynolds Numbers ◽  
Full Scale ◽  
Scale Model ◽  
Current Direction ◽  
Test Results ◽  
Helical Strakes ◽  
Truss Spar ◽  
Scale Data

Floating spar platforms are widely used in the Gulf of Mexico for oil production. The spar is a bluff, vertical cylinder which is subject to Vortex Induced Motions (VIM) when current velocities exceed a few knots. All spars to date have been constructed with helical strakes to mitigate VIM in order to reduce the loads on the risers and moorings. Model tests have indicated that the effectiveness of these strakes is influenced greatly by details of their design, by appurtenances placed on the outside of the hull and by current direction. At this time there is limited full scale data to validate the model test results and little understanding of the mechanisms at work in strake performance. The authors have been investigating the use of CFD as a means for predicting full scale VIM performance and for facilitating the design of spars for reduced VIM. This paper reports on the results of a study to benchmark the CFD results for a truss spar with a set of model experiments carried out in a towing tank. The focus is on the effect of current direction, reduced velocity and strake pitch on the VIM response. The tests were carried out on a 1:40 scale model of an actual truss spar design, and all computations were carried out at model scale. Future study will consider the effect of external appurtenances on the hull and scale-up to full scale Reynolds’ numbers on the results.

Elimination of viruses, bacteria and protozoan oocysts by slow sand filtration

2004 ◽  
Vol 50 (1) ◽  
pp. 147-154 ◽  
Author(s):  
W.A.M. Hijnen ◽  
J.F. Schijven ◽  
P. Bonné ◽  
A. Visser ◽  
G.J. Medema
Keyword(s):  
Pilot Plant ◽  
Pathogenic Bacteria ◽  
Laboratory Experiments ◽  
Full Scale ◽  
Sand Filters ◽  
E Coli ◽  
Thermotolerant Coliforms ◽  
Filter Bed ◽  
Scale Data ◽  
Bacteria Removal

The decimal elimination capacity (DEC) of slow sand filters (SSF) for viruses, bacteria and oocysts of Cryptosporidium has been assessed from full-scale data and pilot plant and laboratory experiments. DEC for viruses calculated from experimental data with MS2-bacteriophages in the pilot plant filters was 1.5-2 log10. E. coli and thermotolerant coliforms (Coli44) were removed at full-scale and in the pilot plant with 2-3 log10. At full-scale, Campylobacter bacteria removal was 1 log10 more than removal of Coli44, which indicated that Coli44 was a conservative surrogate for these pathogenic bacteria. Laboratory experiments with sand columns showed 2-3 and >5-6 log10 removal of spiked spores of sulphite-reducing clostridia (SSRC; C. perfringens) and oocysts of Cryptosporidium respectively. Consequently, SSRC was not a good surrogate to quantify oocyst removal by SSF. Removal of indigenous SSRC by full-scale filters was less efficient than observed in the laboratory columns, probably due to continuous loading of these filter beds with spores, accumulation and retarded transport. It remains to be investigated if this also applies to oocyst removal by SSF. The results additionally showed that the schmutzdecke and accumulation of (in)organic charged compounds in the sand increased the elimination of microorganisms. Removal of the schmutzdecke reduced DEC for bacteria by ±2 log10, but did not affect removal of phages. This clearly indicated that, besides biological activity, both straining and adsorption were important removal mechanisms in the filter bed for microorganisms larger than viruses.

scholarly journals Testing of a Full Scale, Low Emissions, Ceramic Gas Turbine Combustor

1997 ◽  
Author(s):  
K. Smith ◽  
A. Fahme
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Combustion Efficiency ◽  
Full Scale ◽  
Significant Deterioration ◽  
Lean Premixed Combustion ◽  
Fuel Injectors ◽  
Primary Zone ◽  
Test Engine ◽  
Cooling Air

The design and development testing of a full scale, low emissions, ceramic combustor for a 5500 HP industrial gas turbine are described. The combustor was developed under a joint program conducted by the U.S. DOE and Solar Turbines. The ceramic combustor is designed to replace the production Centaur 50S SoLoNOx burner which uses lean-premixed combustion to limit NOx and CO to 25 and 50 ppm, respectively. Both the ceramic and production combustors are annular in shape and employ twelve premixing, natural gas fuel injectors. The ceramic combustor design effort involved the integration of two CFCC cylinders (76.2 cm [30 in.] and 35.56 cm [14 in.] diameters) into the combustor primary zone. The ceramic combustor was evaluated at Solar in full scale test rigs and a test engine. Performance of the combustor was excellent with high combustion efficiency and extremely low NOx and CO emissions. The hot walls of the ceramic combustor played a significant role in reducing CO emissions. This suggests that liner cooling air injected through the metal production liner contributes to CO emissions by reaction quenching at the liner walls. It appears that ceramics can serve to improve combustion efficiency near the combustor lean limit which, in turn, would allow further reductions in NOx emissions. Approximately 50 hours of operation have been accumulated using the ceramic combustor. No significant deterioration in the CFCC liners has been observed. A 4000 hour field test of the combustion system is planned to begin in 1997 as a durability assessment.

An Analysis of the Aerodynamic Characteristics of Split Flaps

1940 ◽  
Vol 44 (352) ◽  
pp. 338-349
Author(s):  
A. P. West
Keyword(s):  
Experimental Data ◽  
Aerodynamic Characteristics ◽  
Full Scale ◽  
The Other ◽  
Aircraft Industry ◽  
The Past ◽  
The Many ◽  
Lift And Drag ◽  
Scale Data

During the past few years an extensive amount of experimental data on split flaps has been made available to the aircraft industry, through the publications of aeronautical research laboratories, both in this country and abroad. In general, each publication deals with one particular aspect of the problem, and when the effect of wing flaps on the performance of an aircraft is being estimated a certain amount of difficulty may be experienced in deciding which of the many reports available gives results most readily applicable to the case being considered ; and what allowances, if any, should be made for wing taper, flap cut-out, fuselage, etc.In this report the available data has been analysed with a view to answering these questions, and presented in such a form that it may be readily applied to determine the most probable change in the aerodynamic characteristics of a wing that may be expected from the use of this type of flap.From the appendix an estimate of the accuracy of the method can be obtained, as a comparison with full-scale data is given for lift and drag, and for the other flap characteristics the original curves have been reproduced.

scholarly journals Planning and Development for a New Generation of Gas Turbine Propelled Ships in the U.S. Navy

1974 ◽  
Author(s):  
R. Goldman ◽  
R. Peterson
Keyword(s):  
World War Ii ◽  
Gas Turbine ◽  
Aircraft Engines ◽  
World War ◽  
Technological Advances ◽  
Prime Movers ◽  
Plant Characteristics ◽  
Base Of Support ◽  
New Generation ◽  
The U.S

In the early 1970s, gas turbine technology had reached the stage where it became feasible to consider marinization of state-of-the-art aircraft engines. Approximately concurrently with these technological advances, the U.S. Navy had the need to project replacements for many of its conventionally propelled surface ships of World War II vintage. Characteristics of good fuel economy coupled with potentially viable reliability and maintenance characteristics conditioned the development of main and auxiliary gas turbine prime movers for ships. Ship design, therefore, was strongly influenced by previously unavailable power plant characteristics. New ships are building and others actively being designed to draw upon these technological advantages, and a broad base of support is being established to ensure the continued long range mobility of the U.S. Navy’s ships.

Determination of textile dyeing wastewater COD components by comparison with respirometry and full‐scale data

2010 ◽  
Vol 31 (11) ◽  
pp. 1191-1201 ◽  
Author(s):  
Jing‐Jie Yu ◽  
Guo‐Wei Gu ◽  
Giovanni Esposito ◽  
Massimiliano Fabbricino ◽  
Shao‐Po Wang ◽  
...  
Keyword(s):  
Full Scale ◽  
Dyeing Wastewater ◽  
Textile Dyeing ◽  
Scale Data ◽  
Textile Dyeing Wastewater

scholarly journals The Role of the Recuperator in High Performance Gas Turbine Applications

1978 ◽  
Author(s):  
C. F. McDonald
Keyword(s):  
High Temperature ◽  
Heat Exchanger ◽  
Gas Turbine ◽  
Gas Turbines ◽  
High Performance ◽  
Waste Heat ◽  
Closed Cycle ◽  
Exhaust Waste Heat ◽  
Prime Movers

With soaring fuel costs and diminishing clean fuel availability, the efficiency of the industrial gas turbine must be improved by utilizing the exhaust waste heat by either incorporating a recuperator or by co-generation, or both. In the future, gas turbines for power generation should be capable of operation on fuels hitherto not exploited in this prime-mover, i.e., coal and nuclear fuel. The recuperative gas turbine can be used for open-cycle, indirect cycle, and closed-cycle applications, the latter now receiving renewed attention because of its adaptability to both fossil (coal) and nuclear (high temperature gas-cooled reactor) heat sources. All of these prime-movers require a viable high temperature heat exchanger for high plant efficiency. In this paper, emphasis is placed on the increasingly important role of the recuperator and the complete spectrum of recuperative gas turbine applications is surveyed, from lightweight propulsion engines, through vehicular and industrial prime-movers, to the large utility size nuclear closed-cycle gas turbine. For each application, the appropriate design criteria, types of recuperator construction (plate-fin or tubular etc.), and heat exchanger material (metal or ceramic) are briefly discussed.

Prediction of First-Order Vessel Responses with Applications to Decision Support Systems

2015 ◽  
Author(s):  
Ulrik D. Nielsen ◽  
Toshio Iseki
Keyword(s):  
Decision Support ◽  
Decision Support Systems ◽  
Support Systems ◽  
Simple Approach ◽  
Full Scale ◽  
Uncertainty Measure ◽  
First Order ◽  
Future Developments ◽  
Vessel Response ◽  
Scale Data

The paper presents a practical and simple approach for making vessel response predictions. Features of the procedure include a) predictions which are scaled so to better agree with corresponding true, future values to be measured at the time the predictions apply at; and b) predictions that are assigned an uncertainty measure to reflect a level of confidence. The approach is tested with full-scale data and the obtained results/predictions agree well with measured values. Potentially, the procedure is therefore very useful in future developments of general decision support systems.

LOCAL STUDIES OF ICE COVER EFFECTS ON DAM GATES

2021 ◽  
Vol 11 (2) ◽  
pp. 62-66
Author(s):  
Sergey V. EVDOKIMOV ◽  
Alexey A. ROMANOV ◽  
Boris G. IVANOV
Keyword(s):  
Power Plants ◽  
Practical Interest ◽  
Full Scale ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Power Stations ◽  
Operation Rules ◽  
Static Operation ◽  
Technical Operation ◽  
Scale Data

The experience of operation of surface emergency gates in ice-breaking conditions at a number of hydroelectric power plants has shown the insuffi cient eff ectiveness of the methods used to combat freezing of structures. The rules for technical operation of spillway dam gates in winter provide for heating of structures by slots, threshold and skin in conjunction with measures to maintain mines before construction. However, measures to heat gates and build mines are not always suffi ciently justifi ed and justifi ed. In order to obtain full-scale data and scientifi c information for the development of recommendations on operating and accounting modes during design, full-scale studies of stresses and defl ections in the load-bearing elements of the watershed gate of the hydroelectric power station were carried out. This article presents the results of fi eld studies in comparison with calculated values. As a result of the studies, information on the static operation of fl at gates in winter conditions is obtained, which is of theoretical and practical interest. The materials can be used to clarify technical operation rules and to clarify regulatory documents for the design of hydromechanical equipment at hydroelectric power stations.

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