Current Navy Research Articles

Editorial

The editorial of Thermal Engineering of this issue continues the discussion on scientific research needs in vital areas in which thermal engineering has important participation. The main goal is to motivate the readers, within their specialties, to identify possible subjects for their future research. The naval sector dominates global commerce totalizing more than 80% of volumes transported]. Heavy fuel oil and marine gas oil are the most utilized fuels and make up 2 to 3% of the human produced CO2 dumped in the atmosphere. Until the year 2050, the International Maritime Organization (IMO) is committed to a 50% reduction of ship greenhouse gases (GHG) emissions with predicted full elimination by 2100. However, military ships are expected to require ten times more electric power than current navy vessels. As a result, the all-electric military ship initiative depends heavily on scientific research and development of environmentally benign high density power generation systems. In that scenario, fuel cells bring a possible path to problem solution. The low-temperature Polymer Electrolyte Membrane Fuel Cell (PEMFC) is recognized to be the most popular FC. Although PEMFC has been used in transportation (e.g., vehicular, ships), PEMFC general use still brings several concerns, due to some shortcomings (e.g., water management, platinum content, Nafion membrane high cost, free energy demanding H2 availability). In parallel, there has been a demand to develop innovative and environmentally correct technologies for alternative energy sources to replace traditional fossil and nuclear sources, including the naval sector, for quite a while, and this need is current, and the main hurdles to overcome are the generation and storage of renewable energy in a technically and economically viable way. The mission of Thermal Engineering is to document the scientific progress in areas related to thermal engineering (e.g., energy, oil and renewable fuels). We are confident that we will continue to receive articles’ submissions that contribute to the progress of science.

The Navy's Earth System Prediction Capability: A New Global Coupled Atmosphere‐Ocean‐Sea Ice Prediction System Designed for Daily to Subseasonal Forecasting

AbstractThis paper describes the new global Navy Earth System Prediction Capability (Navy‐ESPC) coupled atmosphere‐ocean‐sea ice prediction system developed at the Naval Research Laboratory (NRL) for operational forecasting for timescales of days to the subseasonal. Two configurations of the system are validated: (1) a low‐resolution 16‐member ensemble system and (2) a high‐resolution deterministic system. The Navy‐ESPC ensemble system became operational in August 2020, and this is the first time the NRL operational partner, Fleet Numerical Meteorology and Oceanography Center, will provide global coupled atmosphere‐ocean‐sea ice forecasts, with atmospheric forecasts extending past 16 days, and ocean and sea ice ensemble forecasts. A unique aspect of the Navy‐ESPC is that the global ocean model is eddy resolving at 1/12° in the ensemble and at 1/25° in the deterministic configurations. The component models are current Navy operational systems: NAVy Global Environmental Model (NAVGEM) for the atmosphere, HYbrid Coordinate Ocean Model (HYCOM) for the ocean, and Community Ice CodE (CICE) for the sea ice. Physics updates to improve the simulation of equatorial phenomena, particularly the Madden‐Julian Oscillation (MJO), were introduced into NAVGEM. The low‐resolution ensemble configuration and high‐resolution deterministic configuration are evaluated based on analyses and forecasts from January 2017 to January 2018. Navy‐ESPC ensemble forecast skill for large‐scale atmospheric phenomena, such as the MJO, North Atlantic Oscillation (NAO), Antarctic Oscillation (AAO), and other indices, is comparable to that of other numerical weather prediction (NWP) centers. Ensemble forecasts of ocean sea surface temperatures perform better than climatology in the tropics and midlatitudes out to 60 days. In addition, the Navy‐ESPC Pan‐Arctic and Pan‐Antarctic sea ice extent predictions perform better than climatology out to about 45 days, although the skill is dependent on season.

Comparing Performance Category Criteria for U.S. Navy Alternate Physical Readiness Tests

1. Abstract The current Navy Physical Readiness Test (PRT) allows for several alternative methods, in lieu of the 1.5-mile run, with which to assess aerobic fitness. Two of these methods (elliptical trainer and stationary bike) and two additional devices (2-Km rower and 5-Km bike) were evaluated to determine if maximal effort on all devices produced the same performance category as the 1.5-mile run. One hundred thirty-two active-duty military and midshipmen were recruited from the United States Naval Academy and Naval Support Activity Annapolis. Subjects participated in six testing sessions over a six-week period. Subjects performed a 1.5-mile run (n = 118), 12-minute elliptical trainer test (n = 108), 12-minute stationary bike test (n = 115), 2-Km rower test (n = 115), and 5-Km bike test (n = 114). Each performance category attained from the alternate aerobic test device was compared to the performance category attained for the 1.5-mile run. None of the aerobic testing devices performance categories matched well to the 1.5-mile run. The results of the testing sessions support the mandated use of the 1.5-mile run as the sole method of assessing aerobic fitness. Additionally, if an alternate method must be used, the 12-minute stationary bike test using the revised Naval Health Research Center (NHRC) performance categories might be the best option because it has the largest number of performance matching categories. Finally, the results do not support the use of the 12-minute elliptical test, as an authorized alternative, due to its minimal number of matching categories. <span style=font-size:10.0pt;font-family: times= new= roman,serif;mso-fareast-font-family:times= roman=>2. Keywords : Navy; Physical; Readiness <span style=font-size: 10.0pt>

Comparing Alternate Aerobic Tests for United States Navy Physical Readiness Test

ABSTRACTThe current Navy Physical Readiness Test allows for several alternatives to test aerobic fitness. Two currently approved alternate aerobic devices (elliptical trainer and stationary bike) were tested for correlation to VO2max and measured 1.5-mile run times. Two additional devices (2-km rower and 5-km cycle ergometer) were also evaluated as possible alternates. 132 active duty military and Naval Academy midshipmen were recruited from the United States Naval Academy. Subjects participated in six testing sessions over an eight-week period. Subjects performed a VO2max test (n = 96), 1.5 mile run (n = 118), 12-minute stationary bike test (n = 115), 12-minute elliptical trainer test (n = 108), 5-km cycle ergometer test (n = 114), and 2-km rower test (n = 115). Performances in all tests were correlated with one another. The strongest correlation to VO2max existed with the 1.5-mile run (r = –0.84). The 5-km cycle ergometer test (r = –0.42), 2-km rower test (r = –0.42), 12-minute stationary bike test (r = 0.37), and 12-minute elliptical trainer test (r = 0.20) did not correlate as well. For all devices tested, age, gender, and weight were determined to be significant factors when correlating to VO2max and 1.5-mile run times. The results support the mandated use of the 1.5-mile run as the preferred method of assessing aerobic fitness for all sailors. The results do not support the use of the 12-minute elliptical test as an authorized alternative to the 1.5-mile run.

Navy Enhanced Sierra Mechanics (NESM): Toolbox for Predicting Navy Shock and Damage

The US Navy is developing a new suite of computational mechanics tools (Navy Enhanced Sierra Mechanics) for the prediction of ship response, damage, and shock environments transmitted to vital systems during threat weapon encounters. NESM includes fully coupled Euler-Lagrange solvers tailored to ship shock/damage predictions. NESM is optimized to support high-performance computing architectures, providing the physics-based ship response/threat weapon damage predictions needed to support the design and assessment of highly survivable ships. NESM is being employed to support current Navy ship design and acquisition programs while being further developed for future Navy fleet needs.

Work stressors, sleep quality, and alcohol-related problems across deployment: A parallel process latent growth modeling approach among Navy members.

This study examined how work stressors were associated with sleep quality and alcohol-related problems among U.S. Navy members over the course of deployment. Participants were 101 U.S. Navy members assigned to an Arleigh Burke-class destroyer who experienced an 8-month deployment after Operational Enduring Freedom/Operation Iraqi Freedom. Approximately 6weeks prior to deployment, 6weeks after deployment, and 6months reintegration, participants completed measures that assessed work stressors, sleep quality, and alcohol-related problems. A piecewise latent growth model was conducted in which the structural paths assessed if work stressors influenced sleep quality or its growth over time, and in turn if sleep quality influenced alcohol-related problems intercepts or growth over time. A significant indirect effect was found such that increases in work stressors from pre- to postdeployment predicted decreases in sleep quality, which in turn were associated with increases in alcohol-related problems from pre- to postdeployment. These effects were maintained from postdeployment through the 6-month reintegration. Findings suggest that work stressors may have important implications for sleep quality and alcohol-related problems. Positive methods of addressing stress and techniques to improve sleep quality are needed as both may be associated with alcohol-related problems among current Navy members.

A Study on the Introduction and Application Plan of the Mobile Saturation Diving System for ROK Navy Salvage Operations

This study examined how to improve the Korean Navy diving system, particularly focused on using the mobile saturation diving system. This study determined the range of navy operations, and suggested requirements of mobile saturation diving system from the analysis of previous study and current Navy Diving system. Also, this study examined the use of military strategy in terms of its technical and applicable possibility for the enhancement of current system. In addition, the study analyzed both advantages/disadvantages of importing mobile saturation diving system products and domestic development. To review measures in installing and operating such system, this study included analysis on the effectiveness of individual platform. As the result, the study suggested requirements of mobile saturation diving system to be able to be operated by more than 6 divers for more than 17 days at more than 200m depth. And the study confirmed that there are beneficial to use mobile saturation diving system and current Navy saturation diving system together. However, it is low economical efficiency to change current Navy gas diving system to Saturation diving system. To review measures in installing and operating such system, this study suggested that second ATS-II should be built to be able to install mobile saturation diving system. Also, this study generated an utilization method of the system to use it for training when peacetime, and than it should be installed on other platform to use as additional salvage strength during wartime.

Rethinking Nephrolithiasis in Military Aviation

Nephrolithiasis is a common medical condition among aviation personnel that can negatively impact their health and careers. Due to the potentially severe consequences of in-flight renal colic associated with nephrolithiasis, current Navy regulations stipulate extensive evaluation for any aircrew member who has an instance of kidney stones. Two cases of Naval aircrew members with kidney stones are reviewed and current Navy standards regarding nephrolithiasis are discussed. Current Navy standards for granting aeromedical waivers for kidney stones do not differentiate between pilots in actual control of the aircraft and other aircrew members among aircraft personnel. Furthermore, a premium is placed on stone-free status, even for asymptomatic, incidentally found nephroliths. This policy has many similarities, but also significant differences from those of other services and those of civilian aviation authorities. This difference in protocols across aviation communities should be re-examined in order to promote more efficient return to flying duties of operational personnel without compromising safety of flight.

An algorithm to predict surface loss.

A semi‐empirical surface loss algorithm is presented which is comprised of a rough scattering component derived from theory and a term which represents low‐frequency, low angle loss from other mechanisms such as absorption and bubbles, based on a fit to measured data. A prediction of surface duct propagation using the semi‐empirical algorithm and a current Navy standard propagation model is compared to measured data.

A Method to Generate Propulsor Side Forces

A computational study was performed to investigate a method to generate vehicle maneuvering forces from a propulsor alone. A ducted, preswirl propulsor was configured with an upstream stator row and downstream rotor. During normal operation, the upstream stator blades are all situated at the same pitch angle and preswirl the flow into the propulsor while generating a roll moment to counter the moment produced by the rotor. By varying the pitch angles of the stator blade about the circumference, it is possible to both generate a mean stator side force and subsequently vary the axial velocity and swirl that is ingested into the propulsor. The rotor then generates a side force in response to the inflow. Both potential flow and fully viscous 3D Reynolds averaged Navier–Stokes (RANS) computations were used to predict the stator forces, velocity field, and rotor response. Potential flow methods were used for initial examination of a wide variety of stator configurations. The most promising were then modeled using RANS. The RANS inflow was then computed and used as velocity boundary conditions during rotor blade design using potential flow methods. Blade parameters including blade number, rake, skew, and a combination of the two were varied to characterize their effects. RANS was used to then validate the final propulsor design. Computations demonstrated that total side force coefficients on the order of 0.1 and moment coefficients about the stator leading edge of 0.066 could be generated by the propulsor alone. This translates to an additional 50% control authority at 3 kn for current Navy 21″ unmanned undersea vehicles.

What Is Set‐Based Design?

AbstractOn February 4, 2008, Admiral Paul Sullivan, Commander of the Naval Sea Systems Command, sent out a letter entitled: Ship Design and Analysis Tool Goals. The purpose of the widely distributed memorandum was to state the requirements and high‐level capability goals for NAVSEA design synthesis and analysis tools. In this memo, Admiral Sullivan expressed the need for evolving models and analysis tools to be compatible with, among other things, set‐based design (SBD). Admiral Sullivan's memo was a major step toward improving ship design programs with new, more powerful analytical support tools but many have asked, “What is Set‐Based Design and how does it relate to Naval Ship Design?” SBD is a complex design method that requires a shift in how one thinks about and manages design. The SBD paradigm can replace point‐based design construction with design discovery; it allows more of the design effort to proceed concurrently and defers detailed specifications until trade‐offs are more fully understood. This paper describes the principles of SBD citing improvements SBD in design practice that have set the stage for SBD, and relating these principles to current Navy ship design issues.

Developing a Business Case Using Whole Building Performance Measurement

ABSTRACT Since 1998, the U.S. Navy's Naval Facilities Engineering Command (NAVFAC) has had a policy for incorporating sustainable design principles into new building construction. The policy states it is the intent of NAVFAC to accomplish this within the given budget constraints and while meeting customer requirements. Programming a building using a first cost approach instead of a life cycle cost approach is one of the biggest challenges for integrating sustainable design into Navy projects. Due to this hurdle, an attempt to develop a Navy-specific business case was undertaken. Through this process, it was discovered that consistent data were not being collected for all applicable Navy buildings. Therefore, the current business case information being used by the Navy is the conglomeration of existing business case analysis in the literature. Although this business case information is useful, there is still a need for collecting and analyzing the Navy business case. To develop the Navy-specific business case, NAVFAC is developing program metrics to capture the status of buildings in the design and construction phase, and started to collect whole building cost and performance data for 14 buildings (7 sustainably designed and 7 traditionally designed buildings) to capture data on the existing inventory of sustainably designed buildings. Performance measurement data are being collected on water, energy, operations and maintenance, waste generation, purchasing, occupant satisfaction, and transportation. The building cost and performance data will be collected for a minimum of 12 months. Both of these data collection and analysis efforts have offered lessons learned that will be shared alongside the current Navy business case information.

Rightsizing the People's Liberation Army Navy: How Much Naval Force Will Beijing Deploy by 2016?

T he current Chinese navy—the People’s Liberation Army Navy (PLAN)— has since its founding in 1949 labored as an adjunct of the army. It was not until the end of the Cold War and the removal of the Soviet threat that Beijing felt able to direct significantly increased defense resources to modernizing what has throughout its existence been a marginally effective coastal defense force. By 2006 the People’s Republic of China (PRC) had already deployed a navy with the ships, submarines, aircraft and systems ready to serve in pursuit of specific national security objectives, with Taiwan at the head of that list. This process of modernization—which includes improved personnel education and training, further doctrinal development, and a coherent maritime strategic view from Beijing—will almost certainly continue throughout the next decade. By 2016 China will have available as an instrument of national power a navy capable of carrying out assigned missions. The PLAN of 2016, at three times its present size, will dominate East Asian navies—with the possible exception of the Japan Maritime Self-Defense Force (JMSDF)—and will offer a very serious challenge to the U.S. Navy when it operates in that region’s waters. Present trends indicate that by 2016 the Chinese navy will allow Beijing to exert hegemonic leverage in maritime East Asia. This essay offers a brief review of PLAN development to 2016.

Streetfighter ‐ Sampling Alternatives of Analysis for Future Small Combatants

ABSTRACTLooking ahead to the challenges that will confront future navies highlights concern over access to battle space vital to the support of expeditionary operations. The blue water might of the current Navy may not prove successful in addressing this concern. The intent of the discussion that follows is to identify the missions for which the small, fast, inexpensive yet heavily armed surface platform could benefit these types of operations. Following that, an effort has been made to define and address major design issues associated with a ship that embodies these characteristics. The ideas presented are a mix of those already discussed in the open literature and extrapolations thereof.

A Model for Predicting Central Nervous System Oxygen Toxicity from Hyperbaric Oxygen Exposures in Humans

Under certain circumstances, Navy divers breathe 100% O2 when working underwater. Serious symptoms of central nervous system (CNS) O2 toxicity can develop from hyperbaric O2 exposure; immersion and exercise are also known to exacerbate toxicity. We developed risk models for quantitative prediction of the probability of developing symptoms using a large set of human data in which occupational exposure conditions were simulated. Exposures were 5 to 265 min at PO2 levels from 20 to 50 feet of sea water (fsw) (1 fsw = 3.06 kPa). Approximately half of the exposures were to a single PO2, while the remainder were more complicated consisting of exposures to multiple levels of hyperbaric O2. In 688 trials, there were 42 exposure-stopping symptoms. We used maximum likelihood to estimate parameters, likelihood ratios to compare model fits, and chi 2 tests to judge goodness-of-fit of model predictions to observations. The modeling shows that risk has a steep PO2 dependence. A model with autocatalytic features fits the data as well as a simpler model: when PO2 is elevated beyond 34 fsw, risk accumulates rapidly without bound while accumulating toward an asymptote at lower PO2 levels. This autocatalytic feature of risk accumulation implies a testable hypothesis that substantial protection from human CNS O2 toxicity can be obtained from intermittent exposure (periodic exposure to lower PO2). The models predict that the probability of O2 toxicity is less than 7% with current Navy limits while breathing 95% O2. Probability of symptoms is < 1% if FIO2 is maintained at the United States Navy recommended level of 75%.

Industrialization of the Spray Forming Process for Military Applications

Spray forming is a single step gas atomization/deposition process which yields ferrous and non-ferrous near net shape preforms. It has proven to be a viable, cost effective alternative to conventional metal working technology for the production of material preforms with properties surpassing those of their cast and wrought counterparts. Current Navy programs are aimed at optimization of the process, certification of the spray formed products and industrialization of the technology. This includes the development of robust, real-time sensors interfaced with an automated fuzzy logic controller and expanded motion control system. The system will have the capability to manufacture low cost, improved performance, non-symmetric components currently producible only by casting or forging. In addition commercially available spray formed piping from foreign sources is currently being evaluated and certified for near term use in the fleet. Industrialization efforts are underway to establish domestic capabilities as there are no commercial facilities in the United States to date. The Navy has just initiated a manufacturing technology program, the intent of which is to develop a commercial plant in the United States capable of producing large military components. This paper will describe the process and program status. Results and comparative data will be presented and potential new applications discussed.

Performance of an Omnidirectional Wheel on Snow and Ice

ABSTRACTA brief study was performed to investigate the suitability of service vehicles equipped with a unique omnidirectional wheel operating aboard aircraft carriers in northern latitudes, where ice and snow on flight decks is not uncommon. This study addressed the comparative performance of the omnidirectional wheel, a bias‐ply highway tire as used on current Navy MD‐3 aircraft tow vehicles, a typical nonpneumatic forklift truck tire, and an automotive radial‐ply all‐season tire. The tires were tested for driving traction levels on prepared ice, hard‐packed snow, and fresh shallow snow. In general, the omnidirectional wheel showed performance superior to the forklift truck tire and the bias‐ply highway tire. The radial all‐season tire, however, outperformed the omnidirectional wheel in traction on slippery surfaces. The omnidirectional wheel was found to be well‐behaved during traction testing and shows promise for operation on winter surfaces. Recommendations are provided that might further improve omnidirectional wheel performance on snow and ice.

Sound attenuation evaluation of four prototype helmet-integrated ANR systems

Current Navy flight helmets do not provide sufficient passive sound attenuation of the high-intensity, low-frequency noise present in some naval aircraft. As part of a program to provide improved hearing protection for aviators and aircrew personnel, the Naval Aerospace Medical Research Laboratory conducted sound attenuation evaluations of four helmet-integrated active noise reduction (ANR) systems. Sound attenuation measurements (passive attenuation and combined passive/active attenuation) were obtained on Navy and Marine Corps student aviators wearing the prototype helmets in a laboratory noise environment. A Knowles miniature microphone was used to obtain sound levels at the subject's ear. Three sets of measurements were obtained on each subject for each of the prototype systems. A comparison of the combined passive/active attenuation measurements with the passive attenuation measurements reveal increased sound attenuation at 125,250, and 500 Hz and decreased attenuation at 1000 and 2000 Hz. Speech intelligibility measurements obtained on one of the prototypes demonstrated improved speech intelligibility at high sound pressure levels (105 dB and 115 dB) in the ANR “on” mode. [Work supported by the Naval Air Development Center.]

The Navy's new standard digital signal processor, the AN/UYS-2

Current Navy signal processing requirements range from tens of millions to hundreds of millions of multiply-add operations per second. It is expected that these requirements will increase tenfold within the next ten years. To accommodate these expanding requirements, the Navy is building the Signal Processor (AN/UYS-2). The AN/UYS-2 design is driven by the fact that it is the Navy standard signal processor. Being a stantard, it must satisfy more requirements than just high throughput. It must be programmable, modular, expandable, flexible supportable, reliable and provide this capability for the next 20 years to support existing and future users. In order to make it programmable (and therefore reduce the total life cycle ownership cost), the AN/UYS-2 utilizes a Navy developed signal processing graph language methodology called PGM. The implementation of PGM on AN/UYS-2, provides the AN/UYS-2 user with a convenient and cost effective way of specifying the signal proccessing algorithms to be executed for a given application. The AN/UYS-2 desgin approach is to implement PGM and to develop a modular, multiprocessor that could meet a wide range of air, sea, and shore signal processing applications. In order to meet this requirement, a hybrid control-flow/data-flow architecture was chosen to enable evolutionary technology infusion. VLSI component technology is required to implement the primary processing engine in the architecture. The AN/UYS-2 architecture consists of a variable combination of multiple types of Functional Elements (FEs), a data transfer network, a control bus, and a built-in-test (BIT) control bus. This paper provides a review of AN/UYS-2 basic design and growth potential.

Human Performance Assessment to Support Rapid Prototyping and Iterative Design

Fourteen U.S. Navy personnel with Aegis Combat System, Naval Tactical Data System (NTDS), and Non-NTDS operational experience participated in an experiment designed to investigate the impact of proposed workstation designs on operator performance, system usability, and training. Human performance data were collected on a sample of operational procedures typically performed in a Combat Information Center (CIC) for a current Navy Combat System and a prototype workstation. The prototype was developed using specific human factors design principles with the goal of reducing training time, improving operator retention of skills for system operation, reducing errors in system operation, improving operator efficiency (e.g., speed &amp; accuracy of performance), and improving user's satisfaction with the user-computer interface. This paper reports only the preliminary results for data collected from seven subjects who performed procedures using the prototype workstation.