Optimization of the Hybrid Ship Transport Factor through Retrofitted Wave Cancelling Side-Hull Expansions and Bow Bulb

2015 ◽  
Author(s):  
Manivannan Kandasamy ◽  
Ping C. Wu ◽  
Scott Bartlett ◽  
Loc Nguyen ◽  
Frederick Stern
Keyword(s):  
High Performance ◽  
Negative Impact ◽  
Fiscal Year ◽  
Hull Form ◽  
Transport Factor ◽  
Resistance Reduction ◽  
The Us ◽  
Us Navy ◽  
Speed Range ◽  
Design Speed

The US Navy is currently considering the introduction of a Flight III variant beginning with DDG-123 in Fiscal Year 2016. The new design incorporates a new combat system and associated power and cooling upgrades. The overall system improvements increase the payload of the ship and the resulting increased displacement has a negative impact on the service life allowance for range, fuel consumption and sea-keeping characteristics. The present objective is to increase the hull displacement without resistance and sea-keeping penalty and with minimal modifications to the baseline DTMB-5415 design (open literature surrogate of the existing DDG-51 hull form) by using retrofitted blisters in the form of side hull expansions and a bow-bulb. The investigation makes use of high-performance CFD computing for analysis of wave cancellation mechanisms. A candidate modified 5415 design with both blisters and bow bulb shows a resistance reduction of ~11% w.r.t.the baseline 5415 in the design speed range of 15-19 knots, even though the displacement is increased by 8%, such that the transport factor is increased by 19%.

Use of Polysiloxane Coatings for Topside Applications on US Navy Ships

2014 ◽  
Author(s):  
J. Peter Ault ◽  
Pete Lockwood ◽  
Robert Cloutier ◽  
David Kinee
Keyword(s):  
High Performance ◽  
Cost Effective ◽  
Effective Implementation ◽  
High Durability ◽  
Marine Industry ◽  
The Us ◽  
Us Navy ◽  
Oxidation Resistant ◽  
Marine Applications ◽  
Type V

Polysiloxane coatings are the most recent high performance coatings developed to take advantage of the heat and oxidation resistant properties of silicone-based materials. Commercially available polysiloxane coatings predominately consist of organic-inorganic siloxane materials (though some pure siloxane materials are available). Recently, the US Navy has approved polysiloxane coatings as “High Durability” in their specification for exterior weather resistant coatings (MIL-PRF-24635 Type V and VI). Navy approval comes after over 20 years of industry development of polysiloxane coatings for high performance industrial and marine applications, yet issues remain with their cost-effective implementation in the Navy fleet. This paper will review experiences of the offshore and marine industry with polysiloxane coatings and provide an update on the Navy adoption of the technology.

Hull Form Optimization for a 62000DWT Heavy Lift Multi-Purpose Vessel

2021 ◽  
Author(s):  
Shuhui Jiang ◽  
Li Zhang ◽  
Weimin Chen
Keyword(s):  
Optimization Method ◽  
Total Resistance ◽  
Hull Form ◽  
Wake Field ◽  
Resistance Reduction ◽  
Heavy Lift ◽  
Design Speed ◽  
Pressure Resistance ◽  
Profile Optimization ◽  
Viscous Pressure

Abstract A new optimized hull form was proceeded based on a parent ship 60000 DWT bulk carrier. The goal of optimization is to obtain better resistance performance in the loading conditions of scantling draught and design draught. Firstly, the numerical simulation of the parent ship was carried out, the flow field information around the hull was analyzed, the area of high or low pressure was checked, and the area was optimized to make the pressure distribution more uniform. At the same time, the bow entrance section was optimized to reduce the wave-making resistance, and the length of the run body was lengthened to reduce the flow separation area and the viscous pressure resistance. Aiming at these above optimization objectives, the deformation range of hull form was set by commercial software CAESES, and the total resistance of generated optimized cases was solved by SHIPFLOW and evaluated by STARCCM+ software. To grantee the resistance reduction at both design draught and scantling draught, by using the operation profile optimization method, the resistance weights of scantling draught and design draught were set as 50% respectively, that is, the total resistance of optimized hull form equals 50% resistance of design draught condition and 50% resistance of scantling draught condition. The optimization results of total resistance were compared and analyzed, and the cases with relatively minimum total resistance were obtained. On this basis, the wake field at the propeller disk was optimized either, and finally, the target optimization of hull form was obtained. The numerical results showed that, compared with the parent ship, the total resistance at the design speed of the design draught was reduced by about 1.64%, about 2.10% at the design speed of the scantling draught. The wake distribution on the propeller area was more uniform. The final optimized hull form meets the target requirements.

A study into the feasibility of using the oxygen-hydrocarbon engine 11D58M as a basis for development of a high-performance multifunctional gas-generatorless rocket engine with oxygen cooling

2019 ◽  
pp. 67-80
Author(s):  
Boris A. Sokolov ◽  
Nikolay N. Tupitsyn
Keyword(s):  
Film Cooling ◽  
High Performance ◽  
Rocket Engine ◽  
Hydrocarbon Fuel ◽  
Gas Generator ◽  
Automatic Equipment ◽  
The Us ◽  
Upper Stage ◽  
Pump Assembly ◽  
Turbo Pump

The paper presents results of engineering studies and research and development efforts at RSC Energia to analyze and prove the feasibility of using the mass-produced oxygen-hydrocarbon engine 11D58M with 8.5 ton-force thrust as a basis for development of a high-performance multifunctional rocket engine with oxygen cooling and 5 ton-force thrust, which is optimal for upper stages (US), embodying a system that does not include a gas generator. The multi-functionality of the engine implies including in it additional units supporting some functions that are important for US, such as feeding propellant from US tanks to the engine after flying in zero gravity, autonomous control of the engine automatic equipment to support its firing, shutdown, adjustments during burn and emergency protection in case of off-nominal operation, as well as generating torques for controlling the US attitude and stabilizing it during coasting, etc. Replacing conventional engine chamber cooling that uses high-boiling hydrocarbon fuel with the innovative oxygen cooling makes it possible to get rid of the internal film cooling circuits and eliminate their attendant losses of fuel, while the use of the oxygen gasified in the cooling circuit of the chamber to drive the turbo pump assembly permits to design an engine that does not have a gas generator. Key words: Multifunctional rocket engine, oxygen cooling, gas-generatorless design, upper stage.

scholarly journals Reserved Bed Program Reduces Neurosciences Intensive Care Unit Capacity Strain: An Implementation Study

Neurosurgery ◽  
2019 ◽  
Vol 86 (1) ◽  
pp. 132-138
Author(s):  
Christopher D Shank ◽  
Nicholas J Erickson ◽  
David W Miller ◽  
Brittany F Lindsey ◽  
Beverly C Walters
Keyword(s):  
Intensive Care ◽  
Economies Of Scale ◽  
Negative Impact ◽  
The United States ◽  
Fiscal Year ◽  
Implementation Study ◽  
Service Line ◽  
Hospital Units ◽  
Significant Negative Impact ◽  
Operational Issues

Abstract BACKGROUND Neurosciences intensive care units (NICUs) provide institutional centers for specialized care. Despite a demonstrable reduction in morbidity and mortality, NICUs may experience significant capacity strain with resulting supraoptimal utilization and diseconomies of scale. We present an implementation study in the recognition and management of capacity strain within a large NICU in the United States. Excessive resource demand in an NICU creates significant operational issues. OBJECTIVE To evaluate the efficacy of a Reserved Bed Pilot Program (RBPP), implemented to maximize economies of scale, to reduce transfer declines due to lack of capacity, and to increase transfer volume for the neurosciences service-line. METHODS Key performance indicators (KPIs) were created to evaluate RBPP efficacy with respect to primary (strategic) objectives. Operational KPIs were established to evaluate changes in operational throughput for the neurosciences and other service-lines. For each KPI, pilot-period data were compared to the previous fiscal year. RESULTS RBPP implementation resulted in a significant increase in accepted transfer volume to the neurosciences service-line (P = .02). Transfer declines due to capacity decreased significantly (P = .01). Unit utilization significantly improved across service-line units relative to theoretical optima (P < .03). Care regionalization was achieved through a significant reduction in “off-service” patient placement (P = .01). Negative externalities were minimized, with no significant negative impact in the operational KPIs of other evaluated service-lines (P = .11). CONCLUSION Capacity strain is a significant issue for hospital units. Reducing capacity strain can increase unit efficiency, improve resource utilization, and augment service-line throughput. RBPP implementation resulted in a significant improvement in service-line operations, regional access to care, and resource efficiency, with minimal externalities at the institutional level.

scholarly journals 27.2: Invited Paper: Towards High Performance Gate Electrodes: Resistance Reduction in Molybdenum Films by Seed Layer Application

2021 ◽  
Vol 52 (S1) ◽  
pp. 170-174
Author(s):  
Hennrik Schmidt ◽  
Harald Koestenbauer ◽  
Dominik Lorenz ◽  
Christian Linke ◽  
Enrico Franzke ◽  
...  
Keyword(s):  
Seed Layer ◽  
High Performance ◽  
Gate Electrodes ◽  
Resistance Reduction

scholarly journals Ship Handling in Unprotected Waters: A Review of New Technologies in Escort Tugs to Improve Safety

2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa
Keyword(s):  
High Performance ◽  
New Technologies ◽  
Weather Conditions ◽  
Hull Form ◽  
Best Available Technologies ◽  
Adverse Weather Conditions ◽  
Adverse Weather ◽  
New Type ◽  
Technological Challenge ◽  
And Performance

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.

scholarly journals Isolation and Characterization of Nitrate Reducing Bacteria for Conversion of Vegetable-Derived Nitrate to ‘Natural Nitrite’

2021 ◽  
Vol 1 (1) ◽  
pp. 11-23
Author(s):  
Arjun Bhusal ◽  
Peter M. Muriana
Keyword(s):  
Nitrate Reduction ◽  
High Performance ◽  
Limit Of Detection ◽  
Reversed Phase ◽  
Test Tube ◽  
Screening Assay ◽  
Isolation And Characterization ◽  
The Us ◽  
Reducing Bacteria ◽  
Nitrate Reducing Bacteria

In the US, sodium nitrate is used as a preservative and curing agent in processed meats and is therefore a regulated ingredient. Nitrate reducing bacteria (NRB) can convert vegetable nitrate into nitrite allowing green/clean label status in the US as per the USDA-FSIS definition of ‘natural nitrite’. The current ‘in-liquid’ test tube assay for detecting nitrite is not suitable for screening mixtures of bacteria nor is commercial nitrate broth suitable for growth of many Gram (+) bacteria. M17 broth was therefore used to develop M17-nitrate broth to be inclusive of Gram (+) bacteria. An ‘on-agar’ colony-screening assay was developed to detect the conversion of nitrate to nitrite on agar plates and could detect one NRB+ colony among ~300–500 colonies on a single plate. Samples that might have NRB were spread-plated on M17 agar plates, sandwiched with nitrate agar, and after incubation followed with sequential agar overlays containing the reagents used in the nitrate reduction assay; the appearance of red color zones above colonies indicated the presence of nitrite. NRB derived from various samples were confirmed for nitrate conversion and both nitrate and nitrite were quantified by C8 reversed-phase (RP) ion-pairing high performance liquid chromatography (HPLC) analysis (1 ppm limit of detection). Staphylococcus carnosus, a strain commonly used for nitrate reduction, was able to convert 1100 ppm M17-nitrate broth to 917 ppm nitrite. Staphylococcus caprae and Panteoa agglomerans, NRB isolated using the M17-nitrate agar assay, were also able to ferment the same broth to 916 ppm and 867 ppm nitrite, respectively. This is the first report of an on-agar colony screening assay for the detection and isolation of nitrite reducing bacteria allowing NRB to be readily isolated. This may allow for the identification of new bacteria that may have a more efficient process to generate nitrite, and possibly concomitant with production of additional natural antimicrobials, as vegetable nitrite becomes more widely used to prevent spore germination.

scholarly journals Additive Manufacturing of Sensors for Military Monitoring Applications

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1455
Author(s):  
David T. Bird ◽  
Nuggehalli M. Ravindra
Keyword(s):  
Additive Manufacturing ◽  
High Performance ◽  
Sensor Technology ◽  
Distinct Advantage ◽  
Industrial Sectors ◽  
Sensor Fabrication ◽  
The Us ◽  
3D Printed ◽  
Maximum Protection ◽  
The Many

The US Department of Defense (DoD) realizes the many uses of additive manufacturing (AM) as it has become a common fabrication technique for an extensive range of engineering components in several industrial sectors. 3D Printed (3DP) sensor technology offers high-performance features as a way to track individual warfighters on the battlefield, offering protection from threats such as weaponized toxins, bacteria or virus, with real-time monitoring of physiological events, advanced diagnostics, and connected feedback. Maximum protection of the warfighter gives a distinct advantage over adversaries by providing an enhanced awareness of situational threats on the battle field. There is a need to further explore aspects of AM such as higher printing resolution and efficiency, with faster print times and higher performance, sensitivity and optimized fabrication to ensure that soldiers are more safe and lethal to win our nation’s wars and come home safely. A review and comparison of various 3DP techniques for sensor fabrication is presented.

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