Effect of Wedge-Shaped Deflectors on Flow Fields of Dual-Stream Jets

The effect of wedge-shaped fan flow deflectors on the mean and turbulent flow-fields of dual-stream jets is investigated. Several wedge-shaped deflector concepts were used to create asymmetry in the plume of a dual-stream jet issuing from a scaled down version of the NASA Glenn ‘5BB’ bypass-ratio 8 turbofan nozzle. The deflector configurations comprised internal and external wedges with and without a pylon. Some external wedges incorporated local extensions of the fan nacelle. All the deflectors reduced radial velocity gradients, magnitudes of peak Reynolds stresses, and peak turbulent kinetic energy beneath the jet centerplane, with an increase above the jet centerplane. A correlation was obtained between the maximum radial velocity gradient and the peak turbulent kinetic energy in the dominant noise source region

Removal and Reuse of Phosphorus as a Fertilizer from CAFO Runoff

Eutrophication is the process in which nutrient saturated waters promote algal blooms on the surface of the water. This limits the amount of dissolved oxygen content in the water, effectively limiting the range of species that can survive in a body of water. Concentrated animal feeding operations (CAFO) can contribute to this issue. The animals in a CAFO produce large amounts of nutrient-rich waste streams that can enter natural waterways if not properly managed and increase the problem of eutrophication. The ability to treat these waste streams and recover the excess nutrients would allow for not only the reduction of nutrient leaching and runoff but would help create sustainable phosphorus practice. Phosphorus is vital in terms of food production, and there is no replacement for phosphorus for plants or humans. As the population continues to increase, food demand will as well. This means that at any point that phosphorus can be recovered, it should be. To recover phosphorus effectively from waste water sources, reverse osmosis, anion exchange, or adsorption are all viable options. Woo Pig Pooie researched these options for recovering phosphorus, and adsorption was found to be the most promising from standpoints of low maintenance and cost effectiveness. Multiple adsorption materials were ranked based on appropriate performance of cost, particle size, adsorption qualities, and the effects of application of the material. Water treatment residuals, WTR (i.e. spent alum from a drinking water treatment plant), was determined to be the most effective adsorbent. WTR, a waste product, is 80% water as it exits the water treatment plant. It must be pelletized and dried before use as an adsorbent. Pelletized and dried WTR was utilized in a full-scale facility treating 62 GPM of feed using two 11,000 gallons packed columns with associated equipment. If the cost of pelletizing and drying the WTR is included, an alternative strategy for implementation on individual farms is for several farmers to form a cooperative, which would allow the minimization of the $1,460,000 fixed capital cost and the$504,000 cost of manufacturing of the drying pelletizing facility. This would allow for the maximum amount of WTR to be treated increasing the revenue of the operation to $731,500. The cooperative would have an operation of 10 years with a net present value of$5,000. Experimental results using WTR packed columns have shown non-detectable levels of phosphorus in the effluent. The produced phosphorus saturated WTR could be land applied to reduce the level of nutrients in runoff from fields, making a safer agriculture operation

On interference among moving sensors and related problems

We show that for any set of $n$ points moving along "simple" trajectories (i.e., each coordinate is described with a polynomial of bounded degree) in $\Re^d$ and any parameter $2 \le k \le n$, one can select a fixed non-empty subset of the points of size $O(k \log k)$, such that the Voronoi diagram of this subset is "balanced" at any given time (i.e., it contains $O(n/k)$ points per cell). We also show that the bound $O(k \log k)$ is near optimal even for the one dimensional case in which points move linearly in time. As applications, we show that one can assign communication radii to the sensors of a network of $n$ moving sensors so that at any given time their interference is $O(\sqrt{n\log n})$. We also show some results in kinetic approximate range counting and kinetic discrepancy. In order to obtain these results, we extend well-known results from $\varepsilon$-net theory to kinetic environments

Removal and Reuse of Phosphorus as a Fertilizer from CAFO Runoff

Eutrophication is the process in which nutrient saturated waters promote algal blooms on the surface of the water. This limits the amount of dissolved oxygen content in the water, effectively limiting the range of species that can survive in a body of water. Concentrated animal feeding operations (CAFO) can contribute to this issue. The animals in a CAFO produce large amounts of nutrient-rich waste streams that can enter natural waterways if not properly managed and increase the problem of eutrophication. The ability to treat these waste streams and recover the excess nutrients would allow for not only the reduction of nutrient leaching and runoff but would help create sustainable phosphorus practice. Phosphorus is vital in terms of food production, and there is no replacement for phosphorus for plants or humans. As the population continues to increase, food demand will as well. This means that at any point that phosphorus can be recovered, it should be. To recover phosphorus effectively from waste water sources, reverse osmosis, anion exchange, or adsorption are all viable options. Woo Pig Pooie researched these options for recovering phosphorus, and adsorption was found to be the most promising from standpoints of low maintenance and cost effectiveness. Multiple adsorption materials were ranked based on appropriate performance of cost, particle size, adsorption qualities, and the effects of application of the material. Water treatment residuals, WTR (i.e. spent alum from a drinking water treatment plant), was determined to be the most effective adsorbent. WTR, a waste product, is 80% water as it exits the water treatment plant. It must be pelletized and dried before use as an adsorbent. Pelletized and dried WTR was utilized in a full-scale facility treating 62 GPM of feed using two 11,000 gallons packed columns with associated equipment. If the cost of pelletizing and drying the WTR is included, an alternative strategy for implementation on individual farms is for several farmers to form a cooperative, which would allow the minimization of the $1,460,000 fixed capital cost and the$504,000 cost of manufacturing of the drying pelletizing facility. This would allow for the maximum amount of WTR to be treated increasing the revenue of the operation to $731,500. The cooperative would have an operation of 10 years with a net present value of$5,000. Experimental results using WTR packed columns have shown non-detectable levels of phosphorus in the effluent. The produced phosphorus saturated WTR could be land applied to reduce the level of nutrients in runoff from fields, making a safer agriculture operation

Characterizing the Load Environment of Ferry Landings for Washington State Ferries and the Alaska Marine Highway System

INE/AUTC 13.0

Numerical Simulation of Non-Homogeneous Viscous Debris-Flows Based on the Smoothed Particle Hydrodynamics (SPH) Method

Non-homogeneous viscous debris flows are characterized by high density, impact force and destructiveness, and the complexity of the materials they are made of. This has always made these flows challenging to simulate numerically, and to reproduce experimentally debris flow processes. In this study, the formation-movement process of non-homogeneous debris flow under three different soil configurations was simulated numerically by modifying the formulation of collision, friction, and yield stresses for the existing Smoothed Particle Hydrodynamics (SPH) method. The results obtained by applying this modification to the SPH model clearly demonstrated that the configuration where fine and coarse particles are fully mixed, with no specific layering, produces more fluctuations and instability of the debris flow. The kinetic and potential energies of the fluctuating particles calculated for each scenario have been shown to be affected by the water content by focusing on small local areas. Therefore, this study provides a better understanding and new insights regarding intermittent debris flows, and explains the impact of the water content on their formation and movement processes

Opportunities With Decay-At-Rest Neutrinos From Decay-In-Flight Neutrino Beams

Neutrino beam facilities, like spallation neutron facilities, produce copious quantities of neutrinos from the decay at rest of mesons and muons. The viability of decay-in-flight neutrino beams as sites for decay-at-rest neutrino studies has been investigated by calculating expected low-energy neutrino fluxes from the existing Fermilab NuMI beam facility. Decay-at-rest neutrino production in NuMI is found to be roughly equivalent per megawatt to that of spallation facilities, and is concentrated in the facility's target hall and beam stop regions. Interaction rates in 5 and 60 ton liquid argon detectors at a variety of existing and hypothetical locations along the beamline are found to be comparable to the largest existing decay-at-rest datasets for some channels. The physics implications and experimental challenges of such a measurement are discussed, along with prospects for measurements at targeted facilities along a future Fermilab long-baseline neutrino beam.Comment: 6 pages, 3 figure

Offshore Turbine Arrays: Numerical Modeling and Experimental Validation

The interaction between wind turbines in a large wind farm needs to be better understood to reduce array losses and improve energy production. A numerical test bed for an array of offshore wind turbines was developed in the open-source computational fluid dynamics (CFD) framework OpenFOAM. It provides a computational tool which can be used in combination with physical model turbine array studies in the Flow Physics Facility (FPF) at UNH as well as other test facilities. Turbines were modeled as actuator disks with turbulence sources to reduce computational cost. Both k-ϵ and k-ω SST turbulence models were utilized to capture the flow in the near-wall, wake, and free stream regions. Experimental studies were performed in the FPF to validate the numerical results and to provide realistic initial and boundary conditions, for example turbulent boundary layer inlet velocity profiles. Mesh refinement and boundary condition studies were performed. Numerical simulations were executed on a custom-built server, designed to be the head node of a future CFD cluster. The entire project was built on open-source software to facilitate replication and expansion. The numerical model provides building blocks for simulations of large wind turbine arrays, computational resources permitting. The numerical model currently replicates a three by one array of wind turbines in the FPF, and provides detailed insight into the array fluid dynamics

Topological Stability of Kinetic kk-Centers

We study the $k$-center problem in a kinetic setting: given a set of continuously moving points $P$ in the plane, determine a set of $k$ (moving) disks that cover $P$ at every time step, such that the disks are as small as possible at any point in time. Whereas the optimal solution over time may exhibit discontinuous changes, many practical applications require the solution to be stable: the disks must move smoothly over time. Existing results on this problem require the disks to move with a bounded speed, but this model is very hard to work with. Hence, the results are limited and offer little theoretical insight. Instead, we study the topological stability of $k$-centers. Topological stability was recently introduced and simply requires the solution to change continuously, but may do so arbitrarily fast. We prove upper and lower bounds on the ratio between the radii of an optimal but unstable solution and the radii of a topologically stable solution---the topological stability ratio---considering various metrics and various optimization criteria. For $k = 2$ we provide tight bounds, and for small $k > 2$ we can obtain nontrivial lower and upper bounds. Finally, we provide an algorithm to compute the topological stability ratio in polynomial time for constant $k$