Underwater Ordnance Research Articles

Experimental verification of different analytical approaches for estimating underwater explosives

The clearance of underwater ordnance is one of the most complex tasks entrusted to appropriately trained and equipped soldiers. State-of-the-art knowledge in this area is rarely published and is most often possessed by a narrow group of navy specialists. The aim of this paper was to find a link between the existing mathematical models for the peak pressure of underwater explosion with measurements of small charge detonations for long ranges to the observation point in real life scenarios. We have shown the results of the research in which the underwater explosion tests were presented for different TNT equivalents and standoff distances and thus distance ratios. The curves of pressure versus time of ignition were reported. The measurements were confronted with empirical formulas. The comparison showed large, but expected, differences, since the empirical formulas are advised for smaller distance ratios. Based on the conclusions from the study, the new methodology to identify the loading from underwater explosions based on a database collected was postulated. By creating a survey methodology for ships crew for recording explosion parameters, a large number of events can be registered without a strict setup of the test area. The database obtained can be used by military commanders to identify the explosive hazard in the Baltic Sea region.

Study on Effects of The Shape of Cavitator on Supercavitation Flow Field Characteristics

The cavitator is the key part of the nose of the vehicle to induce the formation of supercavity, which has an important influence in the cavity formation rate, cavity shape and cavity stability. To study the influence of the shape on the supercavitation flew field characteristics, the cavity characteristics and the resistance characteristics of different shapes of cavitator under different working conditions are obtained by combining technical methods of numerical simulation and experimental research in water tunnel. The simulation results are contrast and analyzed with the test results. The analysis results show that : in terms of the cavity size, the inverted-conic cavitator can form the biggest cavity size, followed by the disk cavitator, and the truncated-conic cavitator is the least; in terms of the cavity formation speed, the inverted-conic cavitator has the fastest cavity formation speed, then is the truncated-conic cavitator, and the disk cavitator is the least; in terms of the drag characteristic, the truncated-conic cavitator has the maximum coefficient, disk cavitator is the next, the inverted-conic cavitator is the minimal. The research conclusion can provide reference and basis for the head shape design of supercavitating underwater ordnance and the design of hydrodynamic layout.

Deep sea habitats in the chemical warfare dumping areas of the Baltic Sea

The Baltic Sea is a severely disturbed marine ecosystem that has previously been used as a dumping ground for Chemical Warfare Agents (CW). The presence of unexploded underwater ordnance is an additional risk factor for offshore activities and an environmental risk for the natural resources of the sea. In this paper, the focus is on descriptions of the marine habitat based on the observations arising from studies linked to the CHEMSEA, MODUM and DAIMON projects. Investigated areas of Bornholm, Gotland and Gdańsk Deeps are similarly affected by the Baltic Sea eutrophication, however, at depths greater than 70m several differences in local hydrological regimes and pore-water heavy metal concentrations between those basins were observed. During the lifespan of presented studies, we were able to observe the effects of Major Baltic Inflow, that started in December 2014, on local biota and their habitats, especially in the Bornholm Deep area. Reappearance of several meiofauna taxa and one macrofauna specimen was observed approximately one year after this phenomenon, however it's ecological effects already disappeared in March 2017. According to our findings and to the EUNIS Habitat Classification, the three reviewed areas should be characterized as Deep Sea Muddy Sands, while the presence of suspicious bomb-like objects both beneath and on top of the sediments confirms their CW dumpsite status.

An inexpensive underwater mine countermeasures simulator with real-time 3D after action review

Abstract This paper presents the results of a concept capability demonstration pilot study, the aim of which was to investigate how inexpensive gaming software and hardware technologies could be exploited in the development and evaluation of a simulator prototype for training Royal Navy mine clearance divers, specifically focusing on the detection and accurate reporting of the location and condition of underwater ordnance. The simulator was constructed using the Blender open source 3D modelling toolkit and game engine, and featured not only an interactive 3D editor for underwater scenario generation by instructors, but also a real-time, 3D After Action Review (AAR) system for formative assessment and feedback. The simulated scenarios and AAR architecture were based on early human factors observations and briefings conducted at the UK's Defence Diving School (DDS), an organisation that provides basic military diving training for all Royal Navy and Army (Royal Engineers) divers. An experimental pilot study was undertaken to determine whether or not basic navigational and mine detection components of diver performance could be improved as a result of exposing participants to the AAR system, delivered between simulated diving scenarios. The results suggest that the provision of AAR was accompanied by significant performance improvements in the positive identification of simulated underwater ordnance (in contrast to non-ordnance objects) and on participants' description of their location, their immediate in-water or seabed context and their structural condition. Only marginal improvements were found with participants' navigational performance in terms of their deviation accuracies from a pre-programmed expert search path. Overall, this project contributes to the growing corpus of evidence supporting the development of simulators that demonstrate the value of exploiting open source gaming software and the significance of adopting established games design techniques in delivering highly engaging scenarios to defence training communities.

Contributions to the development of underwater acoustics at the Harvard Underwater Sound Laboratory

The Harvard Underwater Sound Laboratory (HUSL) began in June 1941, six months before Pearl Harbor, and closed on January 31, 1946. HUSL was directed throughout its existence by (then) Assoc. Prof. Frederick V. Hunt, who incidentally coined the acronym sonar. This paper traces several contributions HUSL made to undersea warfare through exploitation of underwater acoustics. Especially significant were developments by HUSL in sonar and underwater ordnance (torpedoes). Both developments were supported by numerous subprojects on a wide range of applications such as reverberation suppression, Doppler enhancement, and torpedo transducer design. Particular attention is paid to work on air-dropped and submarine-launched acoustic homing torpedoes. HUSL’s far-reaching influence continues to be evident in today’s sonar and torpedo systems. Closure of HUSL spawned Penn State’s Ordnance Research Laboratory (now Applied Research Laboratory) and enriched sonar development at the US Navy Underwater Sound Laboratory, New London. Moreover, HUSL personnel returning to the University of Texas soon founded the Defense Research Laboratory (now Applied Research Laboratories) at Texas. We pay particular homage to living HUSL alumnus A. Wilson Nolle, who, along with our recently departed colleague, Reuben Wallace, and 12 other deceased alumni, had come to HUSL from the University of Texas.

Comparison of engineered nanocoatings on the combustion of aluminum and copper oxide nanothermites

Water-repellent nano-coatings for submerged combustion of nano-energetic composite materials were developed. These coatings may have applications for oceanic power generation, underwater ordnance, propulsion, metal cutting, and torch technologies. Nano-coatings were deposited on thermite pellets by a vapor-phase technique. Two types of deposition techniques studied were chemical vapor deposition (CVD) and atomic layer deposition (ALD). A total of six types of nano-coatings were applied on the thermite pellets. Various process parameters to produce the coatings were explored. Characterization of the nano-coatings was carried out using Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), and contact angle goniometry. Submerged combustion tests of the nano-coated thermite pellets were performed as a function of submerged time. The pellets were submerged in de-ionized water for 3, 5, and 10days. The energy released by the thermite reaction was analyzed and compared to other types of nano-coated pellets. Initial results of a fluorocarbon self-assembled monolayer (FSAM) coating were compared with an ALD coating composed of Al2O3. Results show that with increasing submerged time, there was a decrease in the ratio of bubble energy to total energy of combustion (Kc=Kbubble/Kcombustion) for all coatings tested. The initial bubble energy of the pellets coated with FSAM and ALD with Al2O3 was 133.3 and 142.2 (KJ/Kg), respectively. After submersion for 10days, the bubble energy reduced to 10.4 and 15.6 (KJ/Kg), respectively. The value of Kc for the FSAM coating decreased by a factor of 12.8 whereas the ALD with Al2O3 coating decreased by a factor of 9.1. The hydrophobic coating is critical for energy generation because without it, the pellets do not ignite, resulting in 100% loss of energy.

Effect of a superhydrophobic coating on the combustion of aluminium and iron oxide nanothermites

There is an interest in broadening the range of applications of nanoenergetic composite materials to include their combustion and energy generation in submerged environments. Currently, their use is primarily limited to gas environments. Oceanic power generation, underwater ordnance, propulsion, metal cutting, and torch technologies are examples of applications that would significantly benefit from nanocomposite energetic materials. Recent research on superhydrophobic coatings has made it possible to coat nanoenergetic samples using a vapor-phase deposition process which significantly reduces the detrimental effects of water entering the composite that can occur during wet-chemistry based superhydrophobic processes. In this work, we discuss the process utilized to produce the superhydrophobic coating on nanoenergetic materials. We then analyze the bubble energy produced and compare this value to other energetic formulations. It was found that the ratio of the bubble energy to the total energy of combustion was an order of magnitude higher for the superhydrophobic coated materials compared to energetic composites containing a hydrophobic binder.

Research and Development A Military—Civilian Partnership

Naval Engineers JournalVolume 79, Issue 6 p. 899-902 Research and Development A Military—Civilian Partnership CAPTAIN THOMAS K. EWAN, CAPTAIN THOMAS K. EWAN USNR THE AUTHOR:serves as Chief, Defense Contract Administration Services Office, Ordnance Aerophysics Laboratory, Daingerfield, Texas. The Writer, as a Reserve Naval Officer and Civilian, has been the Navy's manager of the Ordnance Aerophysics Laboratory since 1945. In World War II he was engaged in underwater Ordnance and Guided Missile Research, Development, Test and Evaluation. He is an active citizen in hospital, youth, scouting and civic activities and a frequent contributor of articles published in this and other journals.Search for more papers by this author CAPTAIN THOMAS K. EWAN, CAPTAIN THOMAS K. EWAN USNR THE AUTHOR:serves as Chief, Defense Contract Administration Services Office, Ordnance Aerophysics Laboratory, Daingerfield, Texas. The Writer, as a Reserve Naval Officer and Civilian, has been the Navy's manager of the Ordnance Aerophysics Laboratory since 1945. In World War II he was engaged in underwater Ordnance and Guided Missile Research, Development, Test and Evaluation. He is an active citizen in hospital, youth, scouting and civic activities and a frequent contributor of articles published in this and other journals.Search for more papers by this author First published: December 1967 https://doi.org/10.1111/j.1559-3584.1967.tb05370.x AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume79, Issue6December 1967Pages 899-902 RelatedInformation

*NEW CONSTRUCTION FIGHTING SHIPS

Naval Engineers JournalVolume 78, Issue 1 p. 49-61 *NEW CONSTRUCTION FIGHTING SHIPS CAPTAIN HOWARD BUCKNELL III, CAPTAIN HOWARD BUCKNELL III U.S. NAVY The author is a graduate of the U.S. Naval Academy class of 1945. His background includes command of USS LSM (R) 514 and USS REMORA (SS489). He has served as a Technical Aide in Underwater Ordnance in the Office of Naval Research, as a guided missile officer in USS CUSK (SSG348), and on the Staff of the Chief of Naval Operations (Submarine Warfare Branch). He graduated from the U.S. Naval War College Command and Staff Course in 1958 and was commissioning Captain of the attack class nuclear powered submarine USS SNOOK (SSN592) which operated as a unit of the Ready HUK group when deployed with the SEVENTH Fleet.Search for more papers by this author CAPTAIN HOWARD BUCKNELL III, CAPTAIN HOWARD BUCKNELL III U.S. NAVY The author is a graduate of the U.S. Naval Academy class of 1945. His background includes command of USS LSM (R) 514 and USS REMORA (SS489). He has served as a Technical Aide in Underwater Ordnance in the Office of Naval Research, as a guided missile officer in USS CUSK (SSG348), and on the Staff of the Chief of Naval Operations (Submarine Warfare Branch). He graduated from the U.S. Naval War College Command and Staff Course in 1958 and was commissioning Captain of the attack class nuclear powered submarine USS SNOOK (SSN592) which operated as a unit of the Ready HUK group when deployed with the SEVENTH Fleet.Search for more papers by this author First published: February 1966 https://doi.org/10.1111/j.1559-3584.1966.tb05039.x * This article is a condensation of a new chapter in the book “Command at Sea” currently under revision by the U.S. Naval Institute. AboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume78, Issue1February 1966Pages 49-61 RelatedInformation

Acoustical Properties of a Free-Edge Bender Disk under Radiation Loading

The vibration of thin disks in a vacuum under various boundary conditions has been extensively treated. Lax, in 1944, analyzed the effect of radiation loading on a clamped-edge vibrating disk. This present paper extends this analysis to arbitrary edge conditions. The technique is to employ the set of orthonormal functions appropriate to the given boundary conditions in vacuo to describe the radiation loading of the disk. The differential equation may be solved simultaneously for the complex coefficients of the expansion either for forced vibrations at a given frequency or for free vibrations in a given mode, solving additionally for the new resonant frequency. The extreme case of free-edge conditions was evaluated in detail. Using a digital computer, numerical values were obtained for the resulting generalized radiation impedances between modes, the complex expansion coefficients, and such quantities as pressure distribution, beam pattern, radiated power, and mechanical Q. [Work supported in part under subcontract to ITT Federal Laboratories, Nutley, N. J., under contract to the U. S. Naval Underwater Ordnance Station, Newport, R. I.]

Analysis of Underwater Acoustic Backscattering from a Random Surface

This paper is essentially a continuation of work presented earlier [J. Acoust. Soc. Am. 36, 1987(A) (1964)]. A mathematical model is hypothesized that yields the backscattered power as a function of incident angle, transducer-beam pattern, frequency, and the waveheight spatial-correlation function. This model considers the surface to be composed of differential facets with dipole beam patterns. The average backscattered power is obtained by squaring the spatial integration of the time-varying signal and averaging in the statistical domain. Curves are presented that compare results from model tank experiments with the analytical results. [This investigation is supported by the Acoustics Program, U. S. Office of Naval Research, and the U. S. Naval Underwater Ordnance Station, Newport, R. I.]

Measurement and Analysis of Underwater Acoustic Backscattering from a Model Ocean Surface

A 12×4×4-ft model tank is utilized to measure the underwater acoustic backscatter from a wind-driven surface. A single transducer is used to transmit and receive a 0.1-msec pulse at a repetition rate of 1000 pulses/sec. The carrier frequency is varied in the range from 200 kc/sec to 2 Mc/sec, which gives an acoustic wavelength/root-mean-square water-waveheight ratio from 0.2 to 2.0. Observations of the relative energy return are made as a function of the incident angle for a fixed path length. A mathematical model is hypothesized that predicts the backscattered energy as a function of incident angle, transducer-beam pattern, frequency, and surface statistics. Curves are presented that compare the observed data with the mathematical model. [This investigation supported by the Acoustics Program, U. S. Office of Naval Research, and the U. S. Naval Underwater Ordnance Station, Newport, R. I.]

Model Study of Signals Reflected from a Wind-Driven Surface

Underwater acoustic-communication experiments are being conducted in a 12×4×4 model tank equipped with a remote-controlled transducer-positioning system and a “sea-state” generator. The model tank is being used so that any individual acoustic path may be investigated without the confusion of multipath interference typical of real ocean channels. Unmodulated and noise modulated 1-Mc/sec acoustic signals are directed at the surface and the reflected signals are recorded. The magnitude of the randomly varying surface is also recorded. These signals are then sampled, digitized, and recorded onto IBM magnetic tape and analyzed on an IBM-1620 computer. Autocorrelation, probability density, and spectral-density functions are calculated for the surface and the amplitude of the received signal. Crosscorrelation and cross-spectral functions between the noise input and the received signal and between the waveheight profile and the received signal are also calculated. This work is an extension of the work reported in paper D4 by the same authors at the 66th ASA Meeting in November 1963. [Work sponsored jointly by the U. S. Office of Naval Research and the U. S. Navy Underwater Ordnance Station, Newport, R. I.]

Statistical Study of the Wind-Driven Surface of an Underwater Acoustic Model Tank

Underwater acoustic signals in general follow a complex paths. One of the important paths is a single bounce off the surface of the ocean. In order to carry on controlled experiments in a model tank, it is necessary to create a model sea state whose characteristics resemble those of the real ocean. It is also important that the statistical characteristics be known and stationary with respect to both time and position on the surface of the water. The model sea state is generated by the movement of air created by a bank of fans mounted at one end of the 12×4×4-ft model tank. The outputs of two instantaneous waveheight indicators are digitized and analyzed on a digital computer. Autocorrelation, crosscorrelation, probability density, and power spectral-density functions are obtained as a function of time and position of the indicators. These functions are compared to real ocean data presently available. [Work supported by the U. S. Office of Naval Research and the U. S. Navy Underwater Ordnance Station, Newport, R. I.]

Some Representative Electronic Subsystem Development Problems in Naval Ordnance

This paper discusses the problems facing the electronic research and development engineer in designing modern naval ordnance equipment. Four distinct areas are presented and are illustrated by the following particular developments: underwater ordnance, missile carried ordnance equipments, equipment intended for field system evaluation and training, and test sets for subsystem testing. Technical details are given on the meteorological rocket HASP, the Miss Distance Measurement System, AN/USQ-11, and applications of the recently developed Solion.

Electronic Instrumentation for Underwater Ordnance Development and Evaluation

An important difference between the underwater weapons of World War II and their predecessors was the use of electronic devices both in the weapons and in the techniques for their development and evaluation. Some of these techniques have now been made available, of which four are described; namely: (1) a recording accelerometer which gives the time-acceleration curve for a missile dropped at high speed into the water; (2) acoustic instrumentation used in the ranging of torpedoes; (3) a system for recording very low-frequency acoustic waves; and (4) a system for telemetering back information from a free weapon operating under water.