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This study analyzed two different inlet management strategies being utilized in Palm Beach County and compared how the downdrift beaches were affected by those strategies throughout the year. Cross-sectional beach profiles, Digital Elevation Model comparisons, and subaerial volumetric change were analyzed for patterns in postplacement beach morphology. Trends in cross- and alongshore grainsize were also analyzed. In Boca Raton the inlet was dredged multiple times a month depending on the level of infilling and the material was placed on the beach immediately downdrift of the inlet. The downdrift beach of the Boca Raton inlet underwent a cycle of shoreline advance in the summer and shoreline retreat in the winter. It was dominated by seasonal processes and its morphologic change was the direct result of shifts in the wind and waves without having a beach more than 60 to 80 meters over the course of the study. In Jupiter, the inlet was dredged on a near annual basis and the material was placed 600m south of the inlet. The size and scope of the larger one-time annual nourishment project resulted in beach widths upwards of 120 meters. The equilibration process that followed in both the cross- and alongshore are what dominated the morphological trends experienced at the site. The results of this study should help coastal managers without current inlet management strategies, compare and overview two different successful inlet management options. For future studies, researchers should extend the monitoring period and extend profiles to the depth of closure to capture. Sediment is a valuable resource, and it’s important for best management practices to maximize benefits and protect downdrift beaches for long-term resiliency of coastal communities., 2022, Includes bibliography., Degree granted: Thesis (MS)--Florida Atlantic University, 2022., Collection: FAU Electronic Theses and Dissertations Collection

Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 123 (2018): 6779-6799, doi:10.1029/2017JC013625., Observations of water levels, waves, currents, and bathymetry collected for a month at an unstratified tidal inlet with a shallow (1 to 2 m deep) ebb shoal are used to evaluate the asymmetry in flows and dynamics owing to inertia and waves. Along‐channel currents ranged from −1.5 to 0.6 m/s (positive inland) inside the main (3 to 5 m deep) channel crossing the ebb shoal. Net discharge is negligible, and ebb dominance of the channel flows is owing to inflow and outflow asymmetries near the inlet mouth. Offshore wave heights ranged from 0.5 to 2.5 m. During moderate to large wave events (offshore significant wave heights >1.2 m), wave forcing enhanced onshore mass flux near the shoal edge and inside the inlet, leading to reduced ebb flow dominance. Momentum balances estimated with the water depths, currents, and waves simulated with a quasi 3‐D numerical model reproduce the momentum balances estimated from the observations reasonably well. Both observations and simulations suggest that ebb‐dominant bottom stresses are balanced by the ebb‐dominant pressure gradient and the tidally asymmetric inertia, which is a sink (source) of momentum on flood (ebb). Simulations with and without waves suggest that waves drive local and nonlocal changes in the water levels and flows. Specifically, breaking waves at the offshore edge of the ebb shoal induce setup and partially block the ebb jet (local effects), which leads to a more onshore‐directed mass flux, changes to the advection across the ebb shoal, and increased water levels inside the inlet mouth (nonlocal effects)., WHOI Coastal Ocean Institute Student Research; Office of the Assistant Secretary of Defense for Research and Engineering; National Defense Science and Engineering; National Science Foundation; Office of Naval Research, 2019-03-22

Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 123 (2018): 6779-6799, doi:10.1029/2017JC013625., Observations of water levels, waves, currents, and bathymetry collected for a month at an unstratified tidal inlet with a shallow (1 to 2 m deep) ebb shoal are used to evaluate the asymmetry in flows and dynamics owing to inertia and waves. Along‐channel currents ranged from −1.5 to 0.6 m/s (positive inland) inside the main (3 to 5 m deep) channel crossing the ebb shoal. Net discharge is negligible, and ebb dominance of the channel flows is owing to inflow and outflow asymmetries near the inlet mouth. Offshore wave heights ranged from 0.5 to 2.5 m. During moderate to large wave events (offshore significant wave heights >1.2 m), wave forcing enhanced onshore mass flux near the shoal edge and inside the inlet, leading to reduced ebb flow dominance. Momentum balances estimated with the water depths, currents, and waves simulated with a quasi 3‐D numerical model reproduce the momentum balances estimated from the observations reasonably well. Both observations and simulations suggest that ebb‐dominant bottom stresses are balanced by the ebb‐dominant pressure gradient and the tidally asymmetric inertia, which is a sink (source) of momentum on flood (ebb). Simulations with and without waves suggest that waves drive local and nonlocal changes in the water levels and flows. Specifically, breaking waves at the offshore edge of the ebb shoal induce setup and partially block the ebb jet (local effects), which leads to a more onshore‐directed mass flux, changes to the advection across the ebb shoal, and increased water levels inside the inlet mouth (nonlocal effects)., WHOI Coastal Ocean Institute Student Research; Office of the Assistant Secretary of Defense for Research and Engineering; National Defense Science and Engineering; National Science Foundation; Office of Naval Research, 2019-03-22

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution March 1984, The offshore tide becomes distorted as it propagates into shallow inlet/estuarine systems. Time asymmetries develop in the rise and fall of sea surface with consequent time and magnitude asymmetries in tidal currents. Flood-dominant estuaries are characterized by longer falling tides and stronger flood currents while ebb-dominant estuaries have longer rising tides and stronger ebb currents. The asymmetries are reflected in the non-linear growth of harmonics and compound tides of the principal equilibrium tidal constituents. This dissertation consists of three papers which examine the development of tidal asymmetries in shallow estuarine systems: a study of the recent migration history of Nauset Inlet (MA), a shallow estuarine system located on Cape Cod; an analysis of the results of a series of field experiments conducted at Nauset; a numerical model study of the types of estuarine characteristics controlling tidal asymmetry. The analysis of field results focuses on sea surface measurements. Non-linear distortion of the tide at Nauset is characterized by the strong growth of harmonics and compound constituents particularly in the quarter-diurnal band. Phase relationships between the forced constituents and their parent produce a flood-dominant estuary. Numerical modeling of M2 tidal propagation in shallow estuarine channels utilizes the one-dimensional equations of motion. Shallow, frictionally dominated channels with moderate tidal flat area develop a flood-dominant asymmetry while deeper channels with extensive tidal flats develop an ebb-dominant asymmetry. Model results are supported by observations of tidal asymmetry in natural estuaries. Implications of non-linear tidal distortion on bedload and suspended material transport are profound. Flood-dominant estuaries tend to import sediment if the supply is adequate whereas ebb-dominant estuaries can flush entering sediment effectively. Over long time periods, flood-dominant estuaries may eventually fill. Ebb-domina, This study was supported by the Department of Commerce, NOAA Office of Sea Grant under Grant numbers NA79AA-D-00102 and NASOAA-D-00077, the U.S. Army Research Office under Grant DAAG 29-81-K-0004, the Woods Hole Oceanographic Institution's Coastal Research Center and the W.H.O.I. education program.

Various aspects of sediment transport in and around natural, unstructured tidal inlets were investigated over the two year period of study. Concentrating on two tidal inlets (Nauset Inlet and Popponesset Inlet, Cape Cod, MA), and combining detailed field observations with numerical model studies of tidal flows in inlet/estuarine environments, several aspects of tidal inlet behavior have been clarified. In addition, field work has resulted in a number of technical publications of general utility to a wide spectrum of coastal research interest. Primary scientific items addressed in this study include: 1) diagnostic numerical model of generation and propagation of tidal non-liniarities in shallow estuarine channels; 2) effects of flow curvature on tidal inlet sediment transport; 3) definition of mechanisms by which tidal inlets migrate in a direction opposite to the net littoral drift direction; 4) hypothesis of a mechanism for rapid barrier spit growth in locations with low rates of littoral transport; 5) clarification of long-term patterns of sea-level rise in the United States to assess its role in tidal inlet/esturarine evolution; 6) historical descriptions of massive inlet migration at two study inlets as supporting evidence for the inlet modeling studies. Technical information generated by the study includes a description of a low-cost, reliable method to join nearshore electrical cables; description and intercomparison of instrumentation and analysis routines for estimating directional spectral parameters from wave gage data; and development of a field system and laboratory analysis package for preparing accurate bathymetric charts in shallow, nearshore regions, using microwave navigation and precision echo-sounding., Funding was provided by the U.S. Army Research Office under Grant DAAG 29-81-K-0004 and the Department of Commerce, NOAA Office of Sea Grant under Grants NA79AA-D-00102 and NA80AA-D-00077.

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution March 1984, The offshore tide becomes distorted as it propagates into shallow inlet/estuarine systems. Time asymmetries develop in the rise and fall of sea surface with consequent time and magnitude asymmetries in tidal currents. Flood-dominant estuaries are characterized by longer falling tides and stronger flood currents while ebb-dominant estuaries have longer rising tides and stronger ebb currents. The asymmetries are reflected in the non-linear growth of harmonics and compound tides of the principal equilibrium tidal constituents. This dissertation consists of three papers which examine the development of tidal asymmetries in shallow estuarine systems: a study of the recent migration history of Nauset Inlet (MA), a shallow estuarine system located on Cape Cod; an analysis of the results of a series of field experiments conducted at Nauset; a numerical model study of the types of estuarine characteristics controlling tidal asymmetry. The analysis of field results focuses on sea surface measurements. Non-linear distortion of the tide at Nauset is characterized by the strong growth of harmonics and compound constituents particularly in the quarter-diurnal band. Phase relationships between the forced constituents and their parent produce a flood-dominant estuary. Numerical modeling of M2 tidal propagation in shallow estuarine channels utilizes the one-dimensional equations of motion. Shallow, frictionally dominated channels with moderate tidal flat area develop a flood-dominant asymmetry while deeper channels with extensive tidal flats develop an ebb-dominant asymmetry. Model results are supported by observations of tidal asymmetry in natural estuaries. Implications of non-linear tidal distortion on bedload and suspended material transport are profound. Flood-dominant estuaries tend to import sediment if the supply is adequate whereas ebb-dominant estuaries can flush entering sediment effectively. Over long time periods, flood-dominant estuaries may eventually fill. Ebb-domina, This study was supported by the Department of Commerce, NOAA Office of Sea Grant under Grant numbers NA79AA-D-00102 and NASOAA-D-00077, the U.S. Army Research Office under Grant DAAG 29-81-K-0004, the Woods Hole Oceanographic Institution's Coastal Research Center and the W.H.O.I. education program.

Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution March 1984, The offshore tide becomes distorted as it propagates into shallow inlet/estuarine systems. Time asymmetries develop in the rise and fall of sea surface with consequent time and magnitude asymmetries in tidal currents. Flood-dominant estuaries are characterized by longer falling tides and stronger flood currents while ebb-dominant estuaries have longer rising tides and stronger ebb currents. The asymmetries are reflected in the non-linear growth of harmonics and compound tides of the principal equilibrium tidal constituents. This dissertation consists of three papers which examine the development of tidal asymmetries in shallow estuarine systems: a study of the recent migration history of Nauset Inlet (MA), a shallow estuarine system located on Cape Cod; an analysis of the results of a series of field experiments conducted at Nauset; a numerical model study of the types of estuarine characteristics controlling tidal asymmetry. The analysis of field results focuses on sea surface measurements. Non-linear distortion of the tide at Nauset is characterized by the strong growth of harmonics and compound constituents particularly in the quarter-diurnal band. Phase relationships between the forced constituents and their parent produce a flood-dominant estuary. Numerical modeling of M2 tidal propagation in shallow estuarine channels utilizes the one-dimensional equations of motion. Shallow, frictionally dominated channels with moderate tidal flat area develop a flood-dominant asymmetry while deeper channels with extensive tidal flats develop an ebb-dominant asymmetry. Model results are supported by observations of tidal asymmetry in natural estuaries. Implications of non-linear tidal distortion on bedload and suspended material transport are profound. Flood-dominant estuaries tend to import sediment if the supply is adequate whereas ebb-dominant estuaries can flush entering sediment effectively. Over long time periods, flood-dominant estuaries may eventually fill. Ebb-domina, This study was supported by the Department of Commerce, NOAA Office of Sea Grant under Grant numbers NA79AA-D-00102 and NASOAA-D-00077, the U.S. Army Research Office under Grant DAAG 29-81-K-0004, the Woods Hole Oceanographic Institution's Coastal Research Center and the W.H.O.I. education program.

Various aspects of sediment transport in and around natural, unstructured tidal inlets were investigated over the two year period of study. Concentrating on two tidal inlets (Nauset Inlet and Popponesset Inlet, Cape Cod, MA), and combining detailed field observations with numerical model studies of tidal flows in inlet/estuarine environments, several aspects of tidal inlet behavior have been clarified. In addition, field work has resulted in a number of technical publications of general utility to a wide spectrum of coastal research interest. Primary scientific items addressed in this study include: 1) diagnostic numerical model of generation and propagation of tidal non-liniarities in shallow estuarine channels; 2) effects of flow curvature on tidal inlet sediment transport; 3) definition of mechanisms by which tidal inlets migrate in a direction opposite to the net littoral drift direction; 4) hypothesis of a mechanism for rapid barrier spit growth in locations with low rates of littoral transport; 5) clarification of long-term patterns of sea-level rise in the United States to assess its role in tidal inlet/esturarine evolution; 6) historical descriptions of massive inlet migration at two study inlets as supporting evidence for the inlet modeling studies. Technical information generated by the study includes a description of a low-cost, reliable method to join nearshore electrical cables; description and intercomparison of instrumentation and analysis routines for estimating directional spectral parameters from wave gage data; and development of a field system and laboratory analysis package for preparing accurate bathymetric charts in shallow, nearshore regions, using microwave navigation and precision echo-sounding., Funding was provided by the U.S. Army Research Office under Grant DAAG 29-81-K-0004 and the Department of Commerce, NOAA Office of Sea Grant under Grants NA79AA-D-00102 and NA80AA-D-00077.

This paper presents the experimental data collected in a series of tests to measure the hydraulic interaction of a typical gully inlet used in the UK. A full-scale laboratory rig was constructed at the University of Sheffield consisting of a testing platform fitted with grated inlets and a gully pot. The gully pot outlet serves both as an outfall and as an inlet to allow surcharge flow into the system. The aim of this paper is to address the shortfall in knowledge, of the flow into and from (surface and below surface) a typical gully system especially during surcharged conditions. This interaction is expressed in terms of head-discharge relationship and is important for the sewer flow simulations of urban flood prediction models. Ultimately, this information may be used by engineers and manufacturers for the design of surface drainage system and for the calibration/validation of coupled urban flood prediction models.

This paper presents the experimental data collected in a series of tests to measure the hydraulic interaction of a typical gully inlet used in the UK. A full-scale laboratory rig was constructed at the University of Sheffield consisting of a testing platform fitted with grated inlets and a gully pot. The gully pot outlet serves both as an outfall and as an inlet to allow surcharge flow into the system. The aim of this paper is to address the shortfall in knowledge, of the flow into and from (surface and below surface) a typical gully system especially during surcharged conditions. This interaction is expressed in terms of head-discharge relationship and is important for the sewer flow simulations of urban flood prediction models. Ultimately, this information may be used by engineers and manufacturers for the design of surface drainage system and for the calibration/validation of coupled urban flood prediction models.

This paper presents the experimental data collected in a series of tests to measure the hydraulic interaction of a typical gully inlet used in the UK. A full-scale laboratory rig was constructed at the University of Sheffield consisting of a testing platform fitted with grated inlets and a gully pot. The gully pot outlet serves both as an outfall and as an inlet to allow surcharge flow into the system. The aim of this paper is to address the shortfall in knowledge, of the flow into and from (surface and below surface) a typical gully system especially during surcharged conditions. This interaction is expressed in terms of head-discharge relationship and is important for the sewer flow simulations of urban flood prediction models. Ultimately, this information may be used by engineers and manufacturers for the design of surface drainage system and for the calibration/validation of coupled urban flood prediction models.

This paper presents the experimental data collected in a series of tests to measure the hydraulic interaction of a typical gully inlet used in the UK. A full-scale laboratory rig was constructed at the University of Sheffield consisting of a testing platform fitted with grated inlets and a gully pot. The gully pot outlet serves both as an outfall and as an inlet to allow surcharge flow into the system. The aim of this paper is to address the shortfall in knowledge, of the flow into and from (surface and below surface) a typical gully system especially during surcharged conditions. This interaction is expressed in terms of head-discharge relationship and is important for the sewer flow simulations of urban flood prediction models. Ultimately, this information may be used by engineers and manufacturers for the design of surface drainage system and for the calibration/validation of coupled urban flood prediction models.

This paper presents the experimental data collected in a series of tests to measure the hydraulic interaction of a typical gully inlet used in the UK. A full-scale laboratory rig was constructed at the University of Sheffield consisting of a testing platform fitted with grated inlets and a gully pot. The gully pot outlet serves both as an outfall and as an inlet to allow surcharge flow into the system. The aim of this paper is to address the shortfall in knowledge, of the flow into and from (surface and below surface) a typical gully system especially during surcharged conditions. This interaction is expressed in terms of head-discharge relationship and is important for the sewer flow simulations of urban flood prediction models. Ultimately, this information may be used by engineers and manufacturers for the design of surface drainage system and for the calibration/validation of coupled urban flood prediction models.

The overall goal of the research is to find diagnostic measurements that reliably indicate changes in the dynamics of hypersonic flow paths ??? scramjet engines in particular. Of primary interest are measurements that serve to indicate that gross changes in flow behavior are about to happen. A priori, it is not known if such measurements exist. Local values of state variables (temperature, pressure, velocity, etc.) will necessarily follow changes. The question is whether or not some particular combination of state variables or an additional measureable quantity or quantities can serve as a precursor of impending dynamic changes. Most interesting for hypersonic engine control are changes in isolator margin, inlet mass capture, and performance (thrust, combustion efficiency, etc.).

The U.S. Army Engineer District, Los Angeles and the Coastal Inlets Research Program have conducted a comprehensive study to investigate wave, flow, sediment transport, and permeable breakwaters with rocky outcrop bottom at Dana Point Harbor, as a part of the harbor revitalization project, on the southern Orange County coast, CA. The 5,500-ft shore-parallel West Breakwater and 2,250-ft shorenormal East Breakwater to protect the harbor are the main interest in the study of the structural integrity and functionality. The field data collection includes 2009 survey of breakwaters, marinas, harbor entrance and surrounding at the harbor, and installation of a pair of ADCPs to measure water levels, waves, and currents inside and outside West Breakwater. The numerical models were used to calculate wave transmission, current and sediment seepage through permeable breakwaters and circulation in the harbor. Permeable breakwaters are simulated by models under wind forcing, tides, bottom friction, and wave reflection. The oceanographic design criteria established previously for the Harbor were updated based on historical storm waves and the present model simulations for 50-yr and 100-yr return periods. The data analysis and model results together provide information to ascertain the action to repair breakwaters and structural alternatives to improve the navigation channel maintenance and tidal flushing in the harbor., The original document contains color images.

This report documents the use of funds awarded by Office of Naval Research (ONR) for the continued operational support of the Research Vessel Pt. Sur and the associated Marine Technician Program., Prepared in cooperation with Moss Landing Marine Laboratories, Moss Landing, CA.

Modern turbine engines require high turbine inlet temperatures and pressures to maximize thermal efficiency. Increasing the turbine inlet temperature drives higher heat loads on the turbine surfaces. In addition, increasing pressure ratio increases the turbine coolant temperature such that the ability to remove heat decreases. As a result, highly effective external film cooling is required to reduce the heat transfer to turbine surfaces. Testing of film cooling on engine hardware at engine temperatures and pressures can be exceedingly difficult and expensive. Thus, modern studies of film cooling are often performed at near ambient conditions. However, these studies are missing an important aspect in their characterization of film cooling effectiveness. Namely, they do not model effect of thermal property variations that occur within the boundary and lm cooling layers at real engine conditions. Also, turbine surfaces can experience significant radiative heat transfer that is not trivial to estimate analytically., The original document contains color images.

This is the second report in a series describing applications with the new shoreline change and sand transport model, GenCade. It is considered as a companion report to the first report in the GenCade series, Frey et al. (2012a), and provides additional details that were not described in that report. This report describes the basic assumptions in GenCade, requirements to run the model, and recommendations about important GenCade capabilities. While all of the basic assumptions are discussed, this report also considers if the assumptions are satisfied and describes a procedure to follow when they are not. All of the required and optional input and output files are explained, and common user errors in model setup, with solutions, are detailed. These user errors may not be evident to new users but are easily corrected. Although the model will run even if the recommendations are not followed, the results may not represent the regional system as well as if properly set up. The recommendations section explains specific capabilities like the regional contour and the Inlet Reservoir Model (IRM) and topics such as project work flow and grid cell spacing. By following these recommendations, the user will produce better results. Finally, the path forward for the model and future guidance are discussed., The original document contains color images.

The demand for increased thrust, higher engine efficiency, and reduced fuel consumption has increased the turbine inlet temperature and pressure in modern gas turbine engines. The outcome of these higher temperatures and pressures is the potential for unconsumed radical species to enter the turbine. Because modern cooling schemes for turbine blades involve injecting cool, oxygen rich air adjacent to the surface, the potential for reaction with radicals in the mainstream flow and augmented heat transfer to the blade arises. This study evaluated various configurations of multiple cylindrical rows of cooling holes in terms of both heat release and effective downstream cooling. It confirmed that a build-up of rows of coolant could be used to effectively protect the wall in a fuel-rich environment. It demonstrated slot and trench configurations to be effective in reducing the heat flux to the wall. Also, the Swirler and Two Row Upstream configurations were shown to highly increase radical consumption. Finally, this research developed infrared imaging as a technique for evaluating the wall temperature of the film cooled surface., The original document contains color images.

Since 2008, the Instituto Español de Oceanografía (IEO) keeps installed a thermosalinometer (TSG) on board of R/V J.M. Navaz that operates on Galician coastal waters. Weekly, it covers the area between Vigo and Muros in the framework of an harmful algal bloom monitoring. High resolution and quality coastal data are very important in order to develop accurate behavior models. The TSG continuously measures the sea subsurface salinity, temperature, and fluorescence along the ships tracks. The classical approach to distribution maps is performing objective analysis of the collected data and assumes errors associated to coastal features. Data-Interpolating Variational Analysis (DIVA) allows the spatial interpolation of data over an adaptable mesh grid, taking into account coastlines and inlets, but also advection constraints. Calculations are optimized and rely on a finite element resolution and the software allows optimizing the analysis parameters, checking for duplicates and performing quality controls. The results of performing and compare DIVA and objective analysis show slight differences that can be appreciated between the inner part of the inlets and the open sea areas. The relative length of the whole data set allows considering also monthly, seasonal and annual variability. These climatological results, that will be updated systematically, can be useful not only for scientific research but also for coastal management activities. All this products, together with quality check flags and metadata information, give added value to the original TSG measures and that will allow a future reuse of data.

The 82d Training Wing (82 TRW) proposes to modify an existing drainage ditch northeast of building 1360 which continues to runway 17/35. and then moves east approximately 1630 feet towards Taxiway D. This would include removing 14 existing headwalls and constructing and enclosing the system underground by using a buried system of pipes and inlets. This Environmental Assessment (EA) is an evaluation of the proposal to modify the existing or migrating through the airfield which poses a safety concern for flying operations, unclogs the drainage ditch by allowing the water to flow down a gradient, and eliminates the effects of standing water and erosion due to being exposed to the elements.

The goal of our effort is to understand river and inlet fluid dynamics through in situ field observations and model validation.

The wave-driven dynamics of coastal areas are important for circulation and mixing, transport processes, and accessibility by vessels. The long-term goal of this study is to improve our understanding, observational capability, and model representation of wave-current interaction in complex coastal inlets, and determine the role of nonlinearity and inhomogeneity on wave statistics in such areas., N00014-23-2-0147

Our long terms goals are to understand sediment transport processes, the relevant physical forcing processes and the resulting morphologic evolution of river mouths and tidal inlets and shoals. Specific goals include understanding bedform characteristics (ripple to sandwave and sandbar scale) in relation to wave- and current-forced mean and turbulent flow., Contract no. N00014-13-1-0767

The long-term goal is to determine the contribution of short-crested breaking waves to vorticity (and thus mixing) in nearshore regions and near strong flows from inlets or river mouths.

Our long terms goals are to understand sediment transport processes, the relevant physical forcing processes and the resulting morphologic evolution of river mouths and tidal inlets and shoals. Specific goals include understanding the interactions between frontal dynamics, turbulence, sediment transport and bedform evolution under extreme current- and wave-forcing conditions.

The primary objective of our studies in FY13 was to develop, test, and improve models for nearshore processes near and within inlet channels. In addition, we continued analysis of our Skagit tidal flats measurements, compared observations with numerical simulations of waves propagating across the shallow, muddy, Louisiana continental shelf, estimated surfzone vorticity and short-crested breaking waves (with David Clark), and investigated the evolution of rip currents and the associated bathymetric channels., Contract nos: N00014-11-10215, N00014-12-10736, N00014-12-10511, N00014-13-10106

The long-range goal of this project is to develop a physics framework, and an associated numerical tool, which provides relatively rapid, phase-resolving predictions of wavy environments in the presence of strong currents and vertical stratification. The benefit of this approach, as contrasted with existing models, is that here we are able to more completely represent the nonlinear wave field, without using coarse statistical approximations, and can include the non-hydrostatic physics introduced by these nearshore wind waves.

A miniature ramjet engine designed to perform at Mach 4.0 was tested in a supersonic wind tunnel. Cryogenic strain gauges were used to measure drag and Schlieren imaging techniques were used to observe the inlet Mach cone profile at Mach numbers of 4.0. Three different nozzle configurations were tested to confirm computational models used to predict back pressure and normal shock locations at the inlet. Using ANSYS-CFX, a cold flow, computational fluid dynamics model of the ramjet in the wind tunnel was evaluated to compare with the experimental results. This model was then used as a base for an eddy dissipation combustion model. Hydrogen was modeled as being injected into the combustion chamber of the ramjet through inlet struts and then reacting with atmospheric oxygen to produce combustion. Drag predictions were inconclusive, however, the computational model remained stable during combustion calculations.

Studies of flow distortion on fundamental scramjet flows have been performed using computational fluid dynamic (CFD) techniques, in conjunction with experimental studies in AFRL/RQH Research Cell 18 (RC18) and Research Cell 19 (RC19). Flow distortion is created in scramjet inlets during flight due to the effects of viscosity near the walls, the effects of shock waves caused by turning the flow, and by the interactions of the viscous boundary layers with shock waves. However, most fundamental scramjet experiments take place in direct-connect test facilities, without an inlet. To support the experimental study of distortion in these direct-connect facilities, CFD was used to design ground test hardware that would create shock waves and boundary layers consistent with flight inlets. Other studies were made on the interaction of these flow distortions with the fuel injection, mixing, and combustion. These studies provide the first detailed investigation of the interaction effects where detailed ground test data is available to validate the computational results. These results have provided key insights into the interaction effects, which will be used to guide the design of scramjet combustors that are tolerant of the anticipated distortion field.

A method is described for the modification and use of a gas chromatograph heated inlet for the preparation of trace vapor reference standards. A conventional GC-MS is used to validate the prepared vapor standards and an evaluation is provided on the reproducibility of replicate measurements made from a single sample as well as individual measurements made between replicate samples. The described method is applied to the preparation of single component trace organic vapors, complex vapor mixtures (containing greater than 10 components over a concentration range spanning four orders of magnitude), and low vapor pressure analytes, which are solids under ambient conditions (e.g., ferrocene). Results demonstrate delivery of picomole quantities of single component organic vapors with a reproducibility of ca. 1% RSD., The original document contains color images.

This report documents preliminary investigations of morphologic change and numerical modeling of wave and current conditions that affect entrance channel navigation at Tillamook Inlet, Oregon. It is believed that unfavorable conditions are caused by a combination of three primary factors: a large ebb shoal, the Pacific coast high-energy wave climate, and a narrow dual-jetty entrance that forms a high current environment. A limited analysis of two bathymetry surveys for representative summer and winter months in 2005 and 2010 indicated that the geometry of ebb shoal outside the entrance of the inlet has been changing, exhibiting an asymmetric orientation relative to the entrance in 2005 which became symmetric by 2010. The historical morphologic evolution of the ebb shoal was evaluated in an attempt to determine possible relationships between the ebb shoal changes and changes to waves and currents in the entrance channel at Tillamook. The numerical modeling analysis was limited to one selected summer month and one winter month, with the sole purpose being the investigation of potential relationships between the geometry (shape, footprint, and elevation) of the ebb shoal and local wave and current conditions during these two selected months. Results indicated that both the geometry of ebb shoal and the entrance jetties together influence the magnitude of waves and currents at the inlet area (through the entrance channel and over the shoal). The two jetties forming the narrow inlet entrance played a critical role in the evolution of the ebb shoal, controlling the spatial variation and severity of waves and currents at the entrance and over the ebb shoal. Wave conditions at Tillamook Inlet may be improved by changing the geometry of the ebb shoal or jetties or both., The original document contains color images.

Spatial and temporal observations of CDOM, salinity and temperature were obtained in New River Inlet, NC to describe the salinity, temperature and optical characterization of a tidally choked estuary with connecting intra-coastal waterways (ICWs). Four different water masses identified as originating from different regions of the estuary, contribute to the characterization of the inlet: 1) ocean (low CDOM, high salinity, and low temperature water), 2) backbay (high CDOM, lower salinity, and warm temperatures), 3) southern ICW (high CDOM, hyper-saline, warm water), and 4) a mixed region. During flood tides, ocean water is transported into the backbay and during ebb tides, backbay water is transported into the ocean. The proximity of the neighboring inlets affects the exchange processes between the southern and northern ICW. The inlet 36km south of New River causes the southern ICW to respond as a tidally choked channel, reducing exchange processes and resulting in increased CDOM, temperature, and salinity. On the contrary, the inlet 12km north of New River Inlet allows free exchange processes between the ocean and the backbay. An interaction exists between the ICWs and the primary inlet tidal channel, where backbay and ocean water are both transported to the ICWs.

This report documents preliminary investigations of morphologic change and numerical modeling of wave and current conditions that affect entrance channel navigation at Tillamook Inlet, Oregon. It is believed that unfavorable conditions are caused by a combination of three primary factors: a large ebb shoal, the Pacific coast high-energy wave climate, and a narrow dual-jetty entrance that forms a high current environment. A limited analysis of two bathymetry surveys for representative summer and winter months in 2005 and 2010 indicated that the geometry of ebb shoal outside the entrance of the inlet has been changing, exhibiting an asymmetric orientation relative to the entrance in 2005 which became symmetric by 2010. The historical morphologic evolution of the ebb shoal was evaluated in an attempt to determine possible relationships between the ebb shoal changes and changes to waves and currents in the entrance channel at Tillamook. The numerical modeling analysis was limited to one selected summer month and one winter month, with the sole purpose being the investigation of potential relationships between the geometry (shape, footprint, and elevation) of the ebb shoal and local wave and current conditions during these two selected months. Results indicated that both the geometry of ebb shoal and the entrance jetties together influence the magnitude of waves and currents at the inlet area (through the entrance channel and over the shoal). The two jetties forming the narrow inlet entrance played a critical role in the evolution of the ebb shoal, controlling the spatial variation and severity of waves and currents at the entrance and over the ebb shoal. Wave conditions at Tillamook Inlet may be improved by changing the geometry of the ebb shoal or jetties or both., The original document contains color images.

Wave blocking in river inlets is examined using the NHWAVE (Non-Hydrostatic Wave) model under development. Blocking flows at river inlets are a significant hazard to navigation. Refractive and shoaling effects contribute to the enhancement of wave field energy, causing instabilities and breaking, resulting in energy dissipation and transfer at the blocking point. The non-linearity of wave-current interactions and wave breaking makes the dynamics of blocking flows difficult to model. Current efforts to use wave-averaged models are insufficient to describe the complex dynamics that occur within one or two wavelengths of a blocking point. NHWAVE uses the non-hydrostatic, incompressible Navier-Stokes equations to model fully dispersive wave processes in the time domain. Monochromatic wave cases are explored and compared with lab experiments of energy dissipation due to wave breaking under conditions of strong opposing current, conducted in 2002 at the University of Delaware by A. Chawla and T. J. Kirby. The model was initially unable to resolve the boundary conditions necessary to model wave blocking in a tank domain. However, developments to the numerical scheme in NHWAVE have advanced its capability in this regard. Due to the difficulties of modeling the dynamics of wave blocking and the boundary conditions in a wave tank, only preliminary results were obtained. NHWAVE needs further development; it shows promise, however, to be able to predict wave reflection, blocking, and dissipation on a strong opposing current.

Our long-term goals include developing and field-testing numerical models of shallow water breaking waves and wave-driven processes, including currents, and tracer transport and dispersion. Improved prediction of the fate of terrestrial runoff pollution and other substances (e.g. fine sediment, chemicals) sometimes present in very shallow water. The objective of this project, to measure mixing and transport in a small tidal inlet, was achieved in the RIVET 1 experiment. During RIVET I, we measured transport and dispersion from within the New River Inlet to 2-3 km offshore and alongshore, at different tidal stages. Analysis of this diverse data set of waves, currents, stratification, Lagrangian drifter, and dye-tracers has begun.

The aim of this paper is to improve and complete the results presented in a previous work published on this journal about an experimental campaign focused on the hydraulic efficiency of continuous transverse grates for draining paved areas. This type of surface drainage structure is commonly used in urban or impervious areas (public squares, airport pavements, parks, and pedestrian areas), where conventional inlets are not recommended because they are rendered ineffective by the lack of a well-defined channelized flow path and gradients capable of directing flows toward the collecting hydraulic structures. In this paper, a methodology is presented to estimate the hydraulic efficiency of nontested continuous transverse grates. Empirical expressions are proposed to relate grate hydraulic performance to flow parameters and grate geometry without the need for laboratory tests. Moreover, the spectrum of the grates was extended in terms of dimensions and hydraulic design with respect to the first study, to enlarge the range of validity of the proposed empirical expressions., Postprint (published version)

A new counterflow virtual impactor (CVI) inlet is introduced with details of its design, laboratory characterisation tests and deployment on an aircraft during the 2011 Eastern Pacific Emitted Aerosol Cloud Experiment (EPEACE). The CVI inlet addresses three key issues in previous designs; in particular, the inlet operates with: (1) negligible organic contamination; (2) a significant sample flow rate to downstream instruments (approx. 15 1 min(-1)) that reduces the need for dilution; and (3) a high level of accessibility to the probe interior for cleaning. Wind tunnel experiments characterised the cut size of sampled droplets and the particle size-dependent transmission efficiency in various parts of the probe. For a range of counter-flow rates and air velocities, the measured cut size was between 8.7-13.1 microns. The mean percentage error between cut size measurements and predictions from aerodynamic drag theory is 1.7 %. The CVI was deployed on the Center for Interdisciplinary Remotely Piloted Aircraft Studies (CIRPAS) Twin Otter for thirty flights during E-PEACE to study aerosol-cloud-radiation interactions off the central coast of California in July and August 2011. Results are reported to assess the performance of the inlet including comparisons of particle number concentration downstream of the CVI and cloud drop number concentration measured by two independent aircraft probes. Measurements downstream of the CVI are also examined from one representative case flight coordinated with shipboard-emitted smoke that was intercepted in cloud by the Twin Otter., Published in the Journal of Atmos. Meas. Tech., v5 p1259-1269, 2012. Continuation of ONR Grant no. N00014-10-1-0200.

The Hayes classification of tidal inlet geomorphic type and the distances from the inlet to the most seaward and down-drift extents of ebb deltas are examined. For this purpose, a database was compiled for 89 tidal inlets along the Atlantic Ocean Gulf of Mexico, and Pacific Ocean coasts of the United States. The database contains spring or diurnal tidal prism and the average significant wave height and wave period from a 20-year hindcast. The Hayes diagram aims to classify inlet plan view morphology by tide range and wave height. Based on the work presented here, it is concluded that the inlet classification of Hayes has limited applicability for describing the morphology of typical tidal inlets, and replacement of tide range by inlet tidal prism did not improve the classification. Best correlation for the two ebb delta extents was found for inlets segregated by wave exposure (as mild, moderate, or high) and by tidal prism. There was poor or no correlation for moderately wave-exposed inlets, and moderate to high correlation was found for mildly and highly exposed inlets. The seaward and down-drift extents of inlets tend to remain constant up to a tidal prism less than 10(8) m(3), depending on wave exposure, and then increase linearly with tidal prism. It is postulated that a tidal prism less than approximately 10(8) m(3) is a tipping point required to overcome other factors controlling tidal inlet plan-form morphology., Published in the Journal of Coastal Research, v28 n3 p547-556, May 2012.

St. Johns County encompasses a 24-km beach and inlet system located in northeast Florida (United States) that includes several interconnected Federal Navigation and Shore Protection Projects that must be managed within a regional context to reduce cost, share sediment, and optimize the volume of sand within the littoral system. The objective of this study is to investigate optimal dredging volumes and intervals, and to determine the beach placement volume and renourishment interval to maintain two Shore Protection Projects. The Coastal Modeling System (CMS) was applied to analyze the morphological impact on the sediment dynamics for ebb-tidal delta mining at St. Augustine Inlet over 1.4-year simulations. Results determined that dredging scenarios under 4 Mill cu yd removed did not significantly modify the ebb-tidal delta. The CMS modeling results on sustainable dredging volumes, combined with historical infilling rates, provided constraints with which to develop dredging and beach fill scenarios for GenCade, a 1-D numerical model that predicts shoreline change. GenCade was applied to evaluate sediment management alternatives for dredging intervals of 5, 7 and 10 years, and varying beach fill volumes and placement lengths. Results indicate that imposing a 10-year dredging interval to the navigation project and ebb delta with the maximum dredging quantity of 3 million cubic yards will yield the best performance of the regional projects of St. Johns County. GenCade calculates future sediment budgets for various management scenarios, and can provide an essential benefit in determining optimal dredging periods for coordinated regional efforts to save in mobilization and demobilization costs for dredging and beach fill placement., Presented at the International Conference on Coastal Engineering held in Santander, Spain on 2-6 July 2012. Sponsored in part by the U.S. Army Corps of Engineers.

Optically dense sprays are often encountered in propulsion applications such as rocket engines. The density of these sprays prevents measurement of droplet diameters and quantitative assessment of spray quality. The lack of quantitative data hinders the development of design criteria and complicates the formation of a fundamental understanding of the impact changes to injector geometry make in an engine's performance. While recent strides have been made in attaining qualitative data on a particular injector - a Gas-Centered Swirl Coaxial injector - with a very dense spray, droplet measurements and spray statistics have remained elusive. The current work presents the first of such quantitative measurements -- measurements achieved using time-resolved x-ray radiography. Details are given on a new experimental set-up used to produce relevant flow conditions at Argonne National Laboratory's Advanced Photon Source and the data processing used to extract droplet diameters and velocities. These extracted data are then used to assess how changes in the geometry of a GCSC injector alter the spray. Changes in liquid inlet diameter and liquid swirl number are shown to impact the spray in unexpected ways. The effect of injector outlet diameter changes and the downstream evolution of the spray are also discussed., The original document contains color images. Presented at the 24th Annual Conference on Liquid Atomization and Spray Systems (ILASS-Americas), San Antonio, TX, 20-23 May 2012.

Principal research goals are to develop tools for characterizing the physics of river flow through a coastal inlet, surface wave processes, and the fate of the plume within the coastal ocean., The original document contains color images.

The overall long-term goal of the Shallow Turbulence in Rivers and Estuaries is to gain a better understanding of turbulent mixing processes and energy dissipation in estuaries and rivers. Specifically, the project goals are to improve understanding of the eddying motion occurring at horizontal length scales greater than the water depth. Improved understanding of such shallow turbulence will facilitate interpretation and utilization of remotely-sensed signatures as observed in rivers and estuaries, and in the vicinity of inlets and river mouths. Calibration and interpretation of non-eddying hydrodynamic models may also be improved, leading to improved modeling of turbulent transport., The original document contains color images.

Our long terms goals are to understand sediment transport processes, the relevant physical forcing processes and the resulting morphologic evolution of river mouths and tidal inlets and shoals. Specific goals include understanding bedform characteristics (ripple to sandwave and sandbar scale) in relation to wave- and current-forced mean and turbulent flow., The original document contains color images.

Our long-term goal is to use remote sensing observations to constrain a data assimilation model of wave and circulation dynamics in an area characterized by a river mouth or tidal inlet and surrounding beaches. As a result of this activity, we will improve environmental parameter estimation via remote sensing fusion, determine the success of using remote sensing data to drive DA models, and produce a dynamically consistent representation of the wave, circulation, and bathymetry fields in complex environments., The original document contains color images.

The wave-driven dynamics of coastal areas are important for circulation and mixing, transport processes, and accessibility by vessels. The long-term goal of this study is to improve our understanding, observational capability, and model representation of wave-current interaction in complex coastal inlets, and determine the role of nonlinearity and inhomogeneity on wave statistics in such areas., The original document contains color images. Prepared in collaboration with Theiss Research, La Jolla, CA under grant nos. N00014-10-1-0411, N00014-11-1-0248.

The long-term objective is to develop field-verified models for the wave fields, circulation patterns, and morphological evolution near inlets and river mouths., The original document contains color images. Sponsored in part by grant nos. N00014-11-1-0799, N00014-12-1-0736, and N00014-12-1-0511.

The overall objectives of this project are as follows: Application of the Wavelet Transform (WT) technique in the spatial domain to characterize the spatial distribution of co-existing bedforms of multiple dimensions generated under different flow field scenarios (waves, unidirectional flows and combined flows). Demonstrate the applicability of WT analysis for the description of bedforms frequently found in coastal and river environments. An improved description of bed features and their interactions will certainly contribute to a more complete understanding of theories describing bedform formation and evolution. Improve overall understanding of small and large scale features, which is especially important because of their strong implications for the associated patterns of bed roughness characteristics, flow resistance and sediment transport. Describe the hydrodynamic interaction of multiple sized bedforms and, conversely, the bed morphology given averaged hydrodynamic parameters; this approach could be used to develop and validate numerical approaches that will allow detailed examination of associated hydrodynamic and morphological conditions at inlets and river mouths., The original document contains color images.