EFFECT OF THE COMBINED NOZZLE ORIENTATION AND TRUCK SPEED ON EFFICACY OF ULTRA-LOW-VOLUME SPRAY AGAINST CAGED AEDES ALBOPICTUS IN URBAN GAINESVILLE, FLORIDA

A field study was conducted to evaluate the combined effect of nozzle orientation and vehicle travel speed on droplet dispersion and mosquito mortality of an adulticide applied from a truck mounted ULV sprayer in the City of Gainesville, Florida. Three multi-block areas with dense, medium, and sparse vegetation were selected for the study. Aqua-Reslin ® was applied in each area in the following treatment combinations: a) horizontal nozzle at 24 km/h travel speed, b) 45° upward orientation (standard) at 16 km/h, and c) 22.5° upward orientation at 24 km/h. Caged, three to five day old Aedes albopictus females were used in all evaluations. Spray deposition was determined at various locations inside each application area using Florida Latham Bonds droplet impingers. There was a significant difference in 24-h mortality among the 3 nozzle angle and speed treatment combinations, but not in the interaction between those combinations and application distance. The 22.5° nozzle combination resulted in the greatest mosquito mortality (88.3%) while the 45° combination resulted in the least mortality (63.1%). A significant difference in 24-h mortality among the 3 vegetation densities and application distances occurred with no significant interaction among these two parameters. The greatest Ae. albopictus mortality was recorded in the sparse (91.4%) and the lowest in the medium vegetation area (72.2%) at the maximum rate of 0.0015 lb./acre. Adulticide deposition was not significantly different among vegetation levels, but was significantly different among the distances and interactions of those parameters.

Contribution of Factors such as Machining Parameters, MQL Nozzle Orientation (Angle & Distance) and MQL Nano-Fluid Type on Surface Finish of Turned Steel Work-Pieces Using DOE Approach

Study of input factors play a vital role in controlling of process responses such as surface finish, cutting temperature, energy consumption etc. in machining process. Design of Experiment (DOE) is one such tool used by researchers to identify the key factors and levels and optimize the process.An attempt was made to identify and experiment turning of AISI 4340 steel using 6 factors viz. cutting speed, feed rate, depth of cut, MQL nozzle orientations (distance from the cutting tool-chip interface, nozzle angle) and different cutting fluid (Coolant). The response variable selected for study was surface roughness of the work-piece which needed to fit criteria smaller-the-better. L25 Orthogonal Array-OA design was selected for 6 factors and 5 levels. Comparison of results of average responses of different levels of factors, analysis of variance (ANOVA) of the process is detailed. Experimental results showed that the key contributors in the turning process are due to cutting speed, feed and depth of cut covering from 12% to 40%. The major contributor to the process was the cutting speed. Selection of MQL fluids and nozzle orientation contributed to 10% showing least significance.This experiment helps us to understand the importance of machine cutting conditions as key success factors which can be assisted with MQL fluids and other input factors.

Particle Image Velocimetry Measurements of Turbulent Jets Issuing From Twin Elliptic Nozzles With Various Orientations

The effects of nozzle orientation on the mixing and turbulent characteristics of elliptical free twin jets were studied experimentally. The experiments were conducted using modified contoured nozzles with a sharp linear contraction. The centers of the nozzle pair had a separation ratio of 5.5. Two nozzle configurations were tested, twin nozzles oriented along the minor plane (Twin_Minor) and twin nozzles oriented along the major plane (Twin_Major) and the results were compared with a single jet. In each case, the Reynolds number based on the maximum jet velocity and the equivalent diameter was 10,000. A planar particle image velocimetry (PIV) system was used to measure the velocity field in the jet symmetry plane. It was observed that the velocity decay rate is not sensitive to nozzle orientation. However, close to the jet exit, the spread rate was highest in the minor plane. In addition, contour plots of swirling strength, Reynolds shear stress and turbulent intensities revealed significant differences between the minor and major planes. Velocity profiles showed little variation close to the jet exit, while further downstream the variations between the velocity profiles were more pronounced between the major and minor planes.

Turbulent Properties of Triple Elliptic Free Jets With Various Nozzle Orientation

An experimental investigation of nozzle orientation effects on turbulent characteristics of elliptic triple free jets was carried out for three nozzle configurations. The first configuration had each nozzle oriented along the minor plane (3_Minor), the next had two nozzles oriented along the minor plane and one along the major plane (Min_Maj_Min) and the last configuration had one nozzle oriented along the minor plane and two along the major plane (Maj_Min_Maj). The experiments were conducted using modified contoured nozzles with a sharp linear contraction for a nozzle spacing ratio of 4.1d, a nozzle equivalent diameter of 9 mm, and Reynolds number of 10,000. Nozzle orientation effects on the mean velocity, turbulent intensity, and Reynolds shear stress were discussed. The velocity decay, jet spread, merging point (MP), combined point (CP), and potential core length were used to characterize the effects of nozzle orientation on the mixing performance. The 3_Minor configuration had shorter potential core length and closer MP location which are indicative of a faster mixing in the converging region. The early merging of 3_Minor led to higher levels of streamwise turbulent intensity. One-dimensional plots revealed that jets approached self-similarity at a faster rate in the major axis. The orientation of the middle jet was found to be a key factor in determining transverse diffusion of the Reynolds shear stress in the plane of observation. Two-point correlations were used to provide insight into the effects of nozzle orientation on the spatial coherence of the large-scale turbulence structure and integral length scale.

Experimental Investigation of Nozzle Orientation Effects on Mixing Characteristics of Elliptic Triple Free Jets

An experimental investigation of nozzle orientation effects on turbulent characteristics of elliptic triple free jets was carried out for three nozzle configurations. The first configuration had all three nozzles oriented along the minor plane (3_Minor), the next had two nozzles oriented along the minor plane and one along the major plane (2_Minor_1_Major) and the last configuration had one nozzle oriented along the minor plane and two along the major plane (1_Minor_2_Major). The experiments were conducted using modified contoured nozzles with a sharp linear contraction for a nozzle-to-nozzle distance of 4.1, a nozzle equivalent diameter of 9 mm and a Reynolds number of 10,000. The effects of nozzle orientation on the mean velocity, turbulence intensity and Reynolds shear stress were discussed. The velocity decay, jet spread, merging point, combined point and potential core length were used to characterize the effects of nozzle orientation on the mixing performance. The results show that the 3_Minor configuration had shorter potential core length and closer merging point location which are indicative of a faster mixing in the converging region. Two-point correlation, skewness and flatness factors were used to provide insight into the effects of nozzle orientation on turbulence structure and higher order turbulence statistics.

The Effects of Nozzle Orientation on Mixing Characteristics of Elliptic Twin Free Jets

The effects of nozzle orientation on the mixing and turbulent characteristics of elliptical free twin jets were studied experimentally. The experiments were conducted using modified contoured nozzles with a sharp linear contraction. The centers of the nozzle pair had a separation ratio of 5.5. Four nozzle configurations were tested, one twin jet orientated along the minor plane (Twin_Minor), one twin jet orientated along the major plane (Twin_Major), one single jet orientated along the minor plane (Single_Minor) and one single jet orientated along the major plane (Single_Major). In each case, the Reynolds number based on the maximum jet velocity and the equivalent diameter was 10,000. A planar particle image velocimetry system was used to measure the velocity field in the jet symmetry plane. It was observed that the velocity decay rate is not sensitive to nozzle orientation. However, close to the jet exit the spread rate was highest in the minor plane. In addition, contour plots of Reynolds shear stress and turbulence intensities revealed significant differences between the minor and major plane. Velocity profiles showed little variation close to the jet exit, while further downstream the variations between the velocity profiles were more pronounced between the major and minor planes.

Nozzle Orientation Effects on the Turbulent Structure of Submerged Twin Jets

Nozzle orientation effects on the turbulent structure of submerged twin jets were investigated experimentally. The twin jets were offset from the free surface by the ratio, h/d = 2, where h is the offset height displacement and d is the nozzle’s hydraulic diameter. The experiments were conducted using a pair of rectangular nozzles having an aspect ratio of 3, oriented in both the minor and major axes. The Reynolds number based on the jet exit velocity and nozzle hydraulic diameter was maintained at 4622. The results show a 74% increase in the attachment length for the nozzle oriented in the major axis relative to the minor. The streamwise velocity at the free surface accelerated at a 58% higher rate for the minor axis orientation compared to that of the major axis. The joint probability density function show a dominance of the fast streamwise fluctuation in the generation of the Reynolds shear stress.

Five-Axis Extrusion-Based Additive Manufacturing of Silicone 3D Contour Nonwoven Fabrics

This study investigates the extrusion-based additive manufacturing (AM) of silicone 3D contour nonwoven fabrics by liquid rope coiling. Customized contour fabrics are ideal for wearable devices for individualized fit and comfort in contact. The AM using silicone liquid rope coiling can fabricate the porous and 3D contour nonwoven fabrics with enhanced breathability and comfortability. The key challenge in the proposed fabrication is the inability to generate consistent coiling pattern because the nozzle orientation deviates from the surface normal vector. A five-axis machine for silicone extrusion AM of nonwoven fabrics was developed to continuously align the nozzle orientation continuously with the surface normal vector. Three cases of silicone printing by coiling were investigated: 1) 3-axis printing, 2) 4-axis printing with nozzle axis normal to the tangent of the toolpath, and 3) 5-axis printing with nozzle axis parallel to the base surface normal. The coiling pattern and geometrical accuracy of the contour fabrics are studied. Results show that the 5-axis AM can generate the consistent coiling pattern and the desired contour geometry to fabricate the silicone 3D contour nonwoven fabrics.