Oil Smoke Research Articles

Instantaneous visualization of surface flows

An experimental system is described for visualizing the surface flow of a wing, using an oil smoke tracer technique. The method leads to the determination of the instantaneous velocity direction at the output of surface injectors. A preliminary investigation is made on a flat plate to optimize the conditions of oil smoke injection. Then, the visualization is performed on the upperside of a sweptback wing in the vicinity of the reattachment of the vortex flow. This visualization technique can be applied to other types of wall flows — separated or not — around various bodies.

Airborne observations of the physical and chemical characteristics of the Kuwait oil smoke plume

Airborne measurements in the densest part of the smoke plume at about 120km from the burning wells in Kuwait in late March 1991 showed typical particulate mass densities of 500–1,000 µgm−3, mixing ratios of 500–1,000 p.p.b.v. of sulphur dioxide and 30–60 p.p.b.v. of nitrogen oxides. One thousand kilometres from Kuwait, ozone concentrations in the plume exceeded background levels by about 50 p.p.b.v. The oil burn rate was estimated from sulphur fluxes to be 3.9 ±1.6 million barrels per day. Significant amounts of smoke were observed only below 5,000m altitude, and the measured attenuation of solar radiation by the smoke was similar to those assumed in recent assessments.

Cloud droplet nucleation by crude oil smoke and coagulated crude oil/wood smoke particles

Cloud condensation nuclei (CCN) measurements are reported, taken on smoke aerosol particle samples generated from the combustion of small quantities of high- and low-sulfur crude oils. The smoke samples were stored in 6 m 3 aging bags, and were analyzed over aging times of more than 50 h. Up to 58% of the high-sulfur crude oil smoke particles were found to be active as CCN at water supersaturation of 1% or less, while 20% were active in the low-sulfur case. Ion chromatography data show the presence of small quantities of inorganic and organic compounds which may be the cause of the CCN activity. The low-sulfur crude oil smoke particles were mixed with wood smoke particles, to see if the resulting aggregates are active as CCN.

Effect of temperature, atmospheric condition, and particle size on extinction in a plume of volatile aerosol dispersed in the atmospheric surface layer

The objective of this work is to study the effects of ambient temperature, atmospheric condition, and particle size on the extinction coefficient of diesel fuel and fog oil smoke. A first-order closure model is used to describe the turbulent diffusion of the smoke in the atmospheric surface layer. Mean values of wind speed and diffusivity in the vertical direction are obtained by the use of the Monin-Obukhov similarity theory. The 2-D crosswind line source model also includes the aerosol kinetic processes of evaporation, sedimentation, and deposition. Numerical results are obtained from simulations on a supercomputer.

Causes of death among workers in a bearing manufacturing plant

Recent studies identify digestive cancer excesses among workers exposed to cutting fluids, abrasive dusts, and oil smoke. Standardized proportional mortality and mortality odds ratio studies were carried out for a ball bearing plant. Cause of death and work histories were obtained for 702 of 768 hourly employees with ten or more years' service who died between 1969 and 1982. Union and company records were used to define exposure measures. The major findings were significant excesses in proportional mortality ratios (PMR) from stomach cancer (PMR = 2.0) and rectal cancer (PMR = 3.1) among white men. After control for age at death, there was a significant association between stomach cancer and precision grinding exposures, consisting primarily of direct contact with water-based cutting fluids (usually emulsified oils) and their aerosols. Some straight oils and synthetic cutting fluids were used as well. The pattern of stomach cancer is consistent with previous findings and suggests an association with the soluble oil cutting fluids.

A Three-Dimensional Turbulent Detached Flow With a Horseshoe Vortex

Static and dynamic mechanisms in a three-dimensional, turbulent, detached flow with a horseshoe vortex, which is encountered in turbomachinery, are clarified experimentally. Flow directional intermittency is obtained by a thermal tuft probe and wall pressure fluctuation survey is performed. Flow visualization is also made by the oil film and smoke wire technique. Four types of vortices exist in the detached region. These vortices are generated by the different process. The detached region is divided into two parts: the region I and II. The flow in the region II, including the detachment point, has dynamic characteristics with low-frequency fluctuation. A new flow model in the detached region is proposed.

Relationships between visible extinction, absorption and mass concentration of carbonaceous smokes

A linear relation, independent of the size distribution, between visible and near-i.r. extinction coefficient σ e (m −1) and mass concentration M (gm −3) of carbonaceous smokes is predicted. For a wavelength λ = 0.55μm the relation is σ e /M = 9.5m 2g −1, assuming a particle density of 2gcm −3. The relation is in good agreement with measurements on coal-fired stack plumes, oil smoke, soot and diesel exhaust that are available in the literature. A similar relationship between carbonaceous smoke visible and near-i.r. absorption coefficient σ a , and mass concentration is also derived. The relations suggest that integrated mass concentration along a path within a carbonaceous smoke cloud can be inferred from measurement of the transmission from one end of the path to the other, and that the mass concentration at a particular location in the cloud can be determined from an in situ measurement of aerosol absorption at that location with a visible or near-i.r. laser spectrophone.

流れの可視化とガス濃度の分析による解析―ガスシールドアーク溶接における耐風効果に関する研究 ＩＩＩ

In this paper we describe an experimental study of the shielding gas flow state in a still atmosphere and windy conditions by visualization of the flow and analyzing the gas concentration around the nozzle. Then a simple method to obtain the suitable gas flow rate of CO2 arc welding in windy condition can be suggested.Results of the experiments are summarized as follows.1) CO2 gas concentration in the wall jet in a still atmosphere is maximum on the plate surface. It decreases lineally parting from the plate surface and decreases exponentially by increasing of X/d.2) CO2 gas concentration of the shielding gas jet in windy conditions is decided by Us, uj, H and d. Each curve showing the relation between qCO2/qCO2+AIR and U0/uj has the similarity throughout the experiment.3) The suitable gas flow rate of the CO2 arc welding in windy conditions can be estimated by the qCO2/qCO2+AIR-U0/uj curve with some H/d used in welding.4) Application of this oil smoke method to visualization of the shielding gas flow is usefull over the wide range of Reynolds number. And this method will be avialble to investigate the shielding gas effect of the narrow-gap welding.

Light scattering functions for particles used in the determination of smoke plume concentration

From a brief discussion of light scattering, the formulae used in the computation of Mie scattering functions are presented. Graphical results are given of the computed total scattering coefficients and angular scattering functions for light incident on spherical droplets comprising an oil smoke. It is shown that, for practical purposes, recurrence formulae may be used for intermediate functions to economize on computer time. Unless increments in size parameter are as small as 0–005, it is not possible to represent the fine structure of the functions adequately. The effect of changes in relative refractive index of smoke particles in the atmosphere due to variations in the environmental temperature is negligible, although the scattering functions increase in complexity as the refractive index increases. For large particles, it is concluded that it is not possible to verify the theoretical curves experimentally, due to the rapid variation of the functions with small changes in particle size. Finally, a brief description is given of the experimental work forming the basis of the research project for which the computations have been made. The annotated programme, written in FORTRAN for an ICL 1905L computer, is printed in the Appendix. Any further information will be supplied on request to the author at the above address.

Powder trail generator for visual sighting of target drones

A prototype powder trail generator was designed, fabricated, flight tested, and delivered to the Naval Air Station, Point Mugu, California. This generator emits a trail of powder with sufficient visibility to aid in the visual acquisition of a target drone. The powder generator functions under conditions that limit the use of oil smoke. Antiagglomerant-treated titanium dioxide pigment was dispersed with a wing pod unit that used high velocity gas jets to deagglomerate the powder before injection into a ram air tube. Flight tests were conducted which compared the powder trail with a conventional oil smoke trail, and aerial photographs showed that the brightness contrast of the powder smoke in the first plane length behind the plane exceeded that of the oil smoke at any location.

The nozzle-fluid concentration field of the round, turbulent, free jet

The light-scatter technique has been used to study the nozzle-fluid concentration field in an isothermal, turbulent, axisymmetric air/air free jet with the nozzle air marked by an oil smoke. The data on the mean concentration field appear to be the most accurate yet obtained, due to the peculiar advantages of the technique. The turbulent concentration fluctuations have been characterized as to intensity, spectral distribution, and two-point correlation. The intermittency factor has been measured and the properties of the turbulent fluid computed. Comparison with the results of other investigators who used heat to mark the nozzle fluid indicates a close similarity between the concentration and temperature fields.

Serendipity and the Development of Experimental Meteorology

Development of cloud physics and discovery of cloud-seeding are reviewed; oil smoke generators; triggering effect of dry ice in changing phase of supercooled cloud; understanding of mountain meteorology improves forecasting of weather phenomena.

More oils but less animal fats

In February 1991 the retreating Iraqi army fired Kuwait's oil wells. Heavy clouds of oil smoke reduced temperatures and illumination along the Saudi Arabian coast, and there was extremely heavy oiling of the shoreline in Saudi Arabia. This paper is part of the output of a mutidisciplinary effort to determine the effects of these events on the Saudi prawn stocks and the fishery they support.In 1991 Saudi Arabian prawn landings fell markedly, with a very low proportion of sexually mature adults. By 1992 the cohort abundance index (t boat−1 yr−1) for adults and juveniles was about 1.5 units compared with a value of 195–205 units for 1989–1990 respectively. The spawning biomass index fell to about 1.8% of the prewar level, a decline capable of causing a recruitment collapse. Independent biomass estimates from trawl surveys showed a decline in total biomass to <1.5% of mean pre-war levels. Landings fell from nearly 4000 t in 1989 to about 25 t in the first half of 1992, causing suspension of the prawn fishery. Yield and biomass per recruit analyses indicate that the stock was not over-fished prior to 1991. A plankton survey (Price et al., 1993) carried out on the spawning grounds showed that penaeid egg/larval abundances were about an order of magnitude lower in 1992 than in earlier years.The evidence suggests that a man made recruitment collapse occurred, caused by one or more of the following: reduced spawning success in 1992 and perhaps in 1991, heavy fishing of adults in spring 1991, heavy fishing of recruits in autumn 1991, morbidity of adults due to pollution in 1991, emigration of adults due to pollution in 1991, interference with biological processes and life cycle of P. semisucaltus, reducing 1991–1992 spawning biomass.All scientific data collection was suspended at the initiation of the Iraq/Kuwait War in August 1990; until late 1991 priority was given to environmental cleaning. Because of this and the lack of detailed biological knowledge about Gulf P. semisulcatus it is impossible to identify the exact pathway through which the prawn stock was impacted. Nevertheless the events associated with the war appear to be the likely cause for failure of the stock.Since causes of the collapse in landings and spawning biomass are not properly identified it is not yet possible to determine whether the stock will recover; and if it does so, the period required for recovery.Reasons why the oil fires and the spill impacted the stock so severely are discussed; the very different effects of this spill and that of the Ixtoc and Nowruz spills are examined. The relevance for other Asian and warm water penaeid fisheries is discussed.

Salts in oil smoke injure slate roof

Salts in oil smoke injure slate roof