Application of an Imaging System to Study Machining Mist Formation via an Atomization Mechanism

2002 ◽  
Author(s):  
C. Ju ◽  
J. Sun ◽  
D. J. Michalek ◽  
J. W. Sutherland
Keyword(s):  
Imaging System ◽  
Health Hazard ◽  
Measurement Range ◽  
Cutting Fluid ◽  
Aerosol Sampling ◽  
Technical Literature ◽  
Model Predictions ◽  
Atomization Mechanism ◽  
Mist Formation ◽  
Rotating Workpiece

Airborne inhalable particulate in the workplace represents a significant health hazard. One of the primary sources of this particulate is mist produced through the application of cutting fluids in machining operations. One of the important mechanisms for the production of cutting fluid mist is the atomization mechanism. In this paper, atomization is studied by applying cutting fluid to a rotating workpiece such as found in turning. An imaging system is presented for the study of the atomization mechanism. The imaging system extends the size measurement range typically achievable with aerosol sampling devices to consider larger particles. Experimental observations from the imaging system reveal that workpiece rotation speed and cutting fluid flow rate have significant effects on the size of the droplets produced by the atomization mechanism. With respect to atomization, the technical literature describes models for fluid interaction with the rotating workpiece and droplet formation via drop and ligament formation modes. Experimental measurements are compared with model predictions. For a range of rotation speeds and fluid application flow rates, the experimental data is seen to compare favorably with the model predictions.

Cutting Fluid Mist Formation in Turning via Atomization: Part 2—Experimental Validation

2000 ◽  
Author(s):  
Y. Yue ◽  
K. L. Gunter ◽  
D. J. Michalek ◽  
J. W. Sutherland
Keyword(s):  
Dynamic Behavior ◽  
Mass Concentration ◽  
Experimental Validation ◽  
Theoretical Models ◽  
Cutting Fluid ◽  
Formation Mechanisms ◽  
Turning Process ◽  
Model Predictions ◽  
Simulation Results ◽  
Mist Formation

Abstract In Part 1 of this paper, models were developed to describe the formation mechanisms and dynamic behavior of cutting fluid mist. This part of the paper focuses on experimentally investigating mist formation during the turning process, and then simulating the dynamic behavior of the mist droplets, including the distribution and the mass concentration. Simulation results are compared to experimental measurements to validate the theoretical models presented in Part 1. It is seen that the model predictions adequately characterize the observed experimental behavior.

Cutting Fluid Mist Formation in Turning via Atomization: Part 1—Model Development

2000 ◽  
Author(s):  
Y. Yue ◽  
K. L. Gunter ◽  
D. J. Michalek ◽  
J. W. Sutherland
Keyword(s):  
Drop Size ◽  
Model Development ◽  
Process Models ◽  
Cutting Fluid ◽  
Additional Information ◽  
Atomization Mechanism ◽  
Series Of Experiments ◽  
Predictive Relationships ◽  
Mist Formation ◽  
Settling Behavior

Abstract Cutting fluid mist is becoming an increasing concern for manufacturers as additional information is obtained on the health risks that it poses. This two-part paper is focused on investigating cutting fluid mist formation via an atomization mechanism in a turning process. Models will be established to predict the fluid mist mean drop size as well as the drop size distribution. Predictive relationships will also be presented for the settling behavior of the fluid mist and the mass concentration. Part 1 of the paper is devoted to the development of the requisite models to describe the mist creation and settling phenomena. In Part 2 of the paper, the mist formation models will be validated through a series of experiments.

OH A2Σ+ –X2Π band ratios observed in the mesosphere by OSIRIS

2008 ◽  
Vol 86 (7) ◽  
pp. 857-862 ◽  
Author(s):  
R L Gattinger ◽  
D A Degenstein ◽  
E J Llewellyn ◽  
M H Stevens
Keyword(s):  
Infrared Imaging ◽  
Vibrational Energy ◽  
Imaging System ◽  
Band System ◽  
Resonance Fluorescence ◽  
Model Predictions ◽  
Spectral Components ◽  
Band Ratios ◽  
Good Agreement

In this study, we present spectra of the mesospheric OH A2Σ+ –X2Π band system, including the 0–0, 1–1, and 1–0 bands, as observed by OSIRIS (Optical Spectrograph and Infrared Imaging System). Spectral components due to Rayleigh-scattered sunlight, lower thermospheric dayglow emission features, and baffle scatter have been removed to isolate the OH emission signature. The observed spectra are compared with model spectra assembled using rotational emission rate factors for solar resonance fluorescence (g-factors) plus prompt emission of the OH A2Σ+ –X2Π band system from solar Lyman-α photodissociation of water. The observed band ratios are in good agreement with the model values. The altitude variation of the 0–0 band, relative to the 1–1 band, is in agreement with model predictions based on vibrational energy transfer from OH A2Σ+ ν′ = 1 to OH A2Σ+ ν′ = 0. This detailed understanding of the OH A2Σ+ –X2Π system is critical for the successful application of OH observations to the determination of mesospheric OH densities and water vapor concentrations.PACS Nos.: 33.20.Lg, 33.20.Tp, 33.70.Fd, 92.60.hc, 92.60.hw

Character and Behavior of Mist Generated by Application of Cutting Fluid to a Rotating Cylindrical Workpiece, Part 1: Model Development

2004 ◽  
Vol 126 (3) ◽  
pp. 417-425 ◽  
Author(s):  
Y. Yue ◽  
J. Sun ◽  
K. L. Gunter ◽  
D. J. Michalek ◽  
J. W. Sutherland
Keyword(s):  
Control Volume ◽  
Film Theory ◽  
Model Development ◽  
Cutting Speed ◽  
Droplet Size Distribution ◽  
Rotating Disk ◽  
Operating Conditions ◽  
Cutting Fluid ◽  
Model Predictions ◽  
Cylindrical Workpiece

Increasing attention is being devoted to the airborne emissions resulting from a variety of manufacturing processes because of health, safety, and environmental concerns. In this two-part paper, a model is presented for the amount of cutting fluid mist produced by the interaction of the fluid with the rotating cylindrical workpiece during a turning operation. This model is based on relationships that describe cutting fluid atomization, droplet settling, and droplet evaporation. Experiments are performed to validate the model. In Part 1 of the paper, the emphasis is on model development. In the model, thin film theory is used to determine the maximum fluid load that can be supported by a rotating cylindrical workpiece; rotating disk atomization theory is applied to the turning process to predict the mean size of the droplets generated by atomization; and expressions for both the evaporation and settling behavior are established. Droplet size distribution and mass concentration predictions are used to characterize the fluid mist. Model predictions indicate that the droplet mean diameter is affected by both fluid properties and operating conditions, with cutting speed having the most significant affect. Model predictions and experimental results show that the number distribution of droplets within the control volume is dominated by small droplets because of the settling and evaporation phenomena. In Part 2 of the paper, the cutting fluid mist behavior model is validated using the results obtained from a series of experiments.

Experimental and Analytical Efforts to Characterize Cutting Fluid Mist Formation and Behavior in Machining

2003 ◽  
Vol 18 (11) ◽  
pp. 842-854 ◽  
Author(s):  
Donna J. Michalek ◽  
Wilson W.-S. Hii ◽  
Jichao Sun ◽  
Kenneth L. Gunter ◽  
John W. Sutherland
Keyword(s):  
Cutting Fluid ◽  
Mist Formation ◽  
And Behavior

Cutting Fluid Aerosol Generation due to Spin-Off in Turning Operation: Analysis for Environmentally Conscious Machining

1999 ◽  
Author(s):  
Zhong Chen ◽  
Kinwah Wong ◽  
Wei Li ◽  
David A. Stephenson ◽  
Steven Y. Liang
Keyword(s):  
Fluid Flow ◽  
Size Distribution ◽  
Health Hazard ◽  
Liquid Sheet ◽  
Machining Process ◽  
Cutting Fluid ◽  
Analytical Models ◽  
Distribution Model ◽  
Shop Floor ◽  
Turning Operation

Abstract This paper presents an analytical model for the prediction of shop floor aerosol concentration and size distribution due to the spinoff of cutting fluid from a rotational workpiece in a turning operation. Based on atomization theory and principles of fluid motion, the model analyzes the generation of cutting fluid aerosol associated with the rotary disk and liquid sheet formations on the workpiece surface. In coupling with fluid flow rate analysis and Rosin and Rammler distribution model, the airborne particulate concentration and size distribution are expressed in terms of fluid properties, fluid application conditions, and machining process parameters. Experiments were performed with the use of light scattering particle measurement device to calibrate and verify the analytical models. Under various fluid flow rates and workpiece rotational speeds, experimental data have shown reasonable agreement with model predictions. The predictive models developed in this paper can be used as a basis for human exposure and health hazard analysis. It can also facilitate the control and optimization of the use of cutting fluids in achieving a balanced consideration of process productivity and environmental consciousness.

Environmentally Conscious Investigation of Cutting Fluid Mist Behavior via Particle Image Velocimetry in Turning

2000 ◽  
Author(s):  
Richard Y. Chiou ◽  
Jim S.-J. Chen ◽  
Derrek Cooper ◽  
Cristian Ciuciu
Keyword(s):  
Particle Image Velocimetry ◽  
Field Experiments ◽  
Particle Image ◽  
Health Hazard ◽  
Near Field ◽  
Ccd Camera ◽  
Cutting Fluid ◽  
Future Research ◽  
Turning Operation ◽  
Image Velocimetry

Abstract In this paper, Particle Image Velocimetry (PIV) monitoring approach for cutting fluid mist behavior in machining is proposed. Particle Image Velocimetry is a technique that uses a combination of lasers and a CCD camera to analyze the fluid flow field. Experiments were performed to investigate the transient mist patterns due to the impinging cutting fluid on a rotational workpiece in a turning operation. The measurements displayed the velocity profiles and sizes of the generated fluid mist both in the near-field and far-field. This paper contains the results of a preliminary experiment to measure and analyze mist generation mechanism on a lathe. The experimental investigation concerning the mist behavior in a turning operation can be used as basis for human exposure and health hazard analysis. Some preliminary results were obtained and recommendations were made for future research.

MAPPING OIL SPILL THICKNESS WITH A PORTABLE MULTISPECTRAL AERIAL IMAGER

2008 ◽  
Vol 2008 (1) ◽  
pp. 131-136 ◽  
Author(s):  
Jan Svejkovsky ◽  
Judd Muskat ◽  
Joseph Mullin
Keyword(s):  
Imaging System ◽  
Rapid Determination ◽  
Free Water ◽  
Image Data ◽  
Visual Assessment ◽  
Thickness Measurement ◽  
Measurement Range ◽  
Additional Information ◽  
Natural Oil ◽  
Oil Thickness

ABSTRACT Rapid determination of oil thickness patterns within a spill at sea is vital for efficient planning and management of spill response activities. Presently such determinations are made almost solely by airborne visual surveys which require specially trained observers and are prone to errors due to variations in illumination, water color, and other environmental conditions. Our goal is to eliminate the subjectivity of visual assessment techniques by developing a computerized portable imaging system that could provide detailed maps of oil-on-water thickness distributions in near-realtime. We have developed oil thickness determination algorithms that utilize multispectral images from a 4-channel sensor providing oil reflectance data in the UV and three channels between 500 and 700nm. A neural network-based algorithm first isolates all oil-on-water areas from oil-free water, sunglint and other potential artifacts. A fuzzy ratio classification algorithm then maps the oil-contaminated areas for thickness classes. The reflectance ratio-based algorithms were tested with several types of crude and fuel oils at MMS’ Ohmsett facility as well as over natural oil seepage areas in the Santa Barbara Channel, California. The methodology yielded accurate thickness estimates over oil films ranging from sheens to 0.2–0.3mm thick. Although the location of thicker films can be accurately mapped, their absolute thickness cannot be established using the UV-visible wavelength range. The addition of an infrared channel may expand the system'S thickness measurement range and is presently being investigated. The imager also allows the identification of emulsified vs. unemulsified oil, thus providing additional information to help guide efficient spill response. Real-time image processing capabilities are presently being developed to allow the system to disseminate a GIS-compatible map immediately after image data acquisition.

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