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All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Floating Oil-Spill Containment Device

Previous oil containment booms have an open top that allows natural gas to escape, and have significant oil leakage due to wave action. Also, a subsea pyramid oil trap exists, but cannot move relative to moving oil plumes from deepsea oil leaks. The solution is to have large, moveable oil traps. One version floats on the sea surface and has a flexible tarp cover and a lower weighted skirt to completely entrap the floating oil and natural gas. The device must have at least three sides with boats pulling at each apex, and sonar or other system to track the slowly moving oil plume, so that the boats can properly locate the booms. The oil trap device must also have a means for removal of the oil and the natural gas. A second design version has a flexible pyramid cover that is attached by lines to ballast on the ocean floor. This is similar to fixed, metal pyramid oil capture devices in the Santa Barbara Channel off the coast of California. The ballast lines for the improved design, however, would have winches that can move the pyramid to always be located above the oil and gas plume. A third design is a combination of the first two. It uses a submerged pyramid to trap oil, but has no anchor and uses boats to locate the trap. It has ballast weights located along the bottom of the tarp and/or at the corners of the trap. The improved floating oil-spill containment device has a large floating boom and weighted skirt surrounding the oil and gas entrapment area. The device is triangular (or more than three sides) and has a flexible tarp cover with a raised gas vent area. Boats pull on the apex of the triangles to maintain tension and to allow the device to move to optimum locations to trap oil and gas. The gas is retrieved from a higher buoyant part of the tarp, and oil is retrieved from the floating oil layer contained in the device. These devices can be operated in relatively severe weather, since waves will break over the devices without causing oil leaking. Also, natural gas is entrapped and can be retrieved. All designs can use sonar to locate the moving oil plume, and then be relocated by using boats or winches to move the oil trapping devices. These devices can be constructed of treated, non-permeable DuPont Kevlar cloth (or similar material).

Jones, Jack A.↗
NASA NTRS2006

System for Continuous Deaeration of Hydraulic Oil

A system for continuous, rapid deaeration of hydraulic oil has been built to replace a prior system that effected deaeration more slowly in a cyclic pressure/ vacuum process. Such systems are needed because (1) hydraulic oil has an affinity for air, typically containing between 10 and 15 volume percent of air and (2) in the original application for which these systems were built, there is a requirement to keep the proportion of dissolved air below 1 volume percent because a greater proportion can lead to pump cavitation and excessive softness in hydraulic-actuator force-versus-displacement characteristics. In addition to overcoming several deficiencies of the prior deaeration system, the present system removes water from the oil. The system (see figure) includes a pump that continuously circulates oil at a rate of 10 gal/min (38 L/min) between an 80-gal (303-L) airless reservoir and a tank containing a vacuum. When the circulation pump is started, oil is pumped, at a pressure of 120 psi (827 kPa), through a venturi tube below the tank with a connection to a stand-pipe in the tank. This action draws oil out of the tank via the standpipe. At the same time, oil is sprayed into the tank in a fine mist, thereby exposing a large amount of oil to the vacuum. When the oil level in the tank falls below the lower of two level switches, a vacuum pump is started, drawing a hard vacuum on the tank through a trap that collects any oil and water entrained in the airflow. When the oil level rises above higher of the two level switches or when the system is shut down, a solenoid valve between the tank and the vacuum pump is closed to prevent suction of oil into the vacuum pump. Critical requirements that the system is designed to satisfy include the following: 1) The circulation pump must have sufficient volume and pressure to operate the venturi tube and spray nozzles. 2) The venturi tube must be sized to empty the tank (except for the oil retained by the standpipe) and maintain a vacuum against the vacuum pump. 3) The tank must be strong enough to withstand atmospheric pressure against the vacuum inside and must have sufficient volume to enable exposure of a sufficiently large amount of sprayed oil to the vacuum. 4) The spray nozzles must be sized to atomize the oil and to ensure that the rate of flow of sprayed oil does not exceed the rate at which the venturi action can empty the tank. 5) The vacuum pump must produce a hard vacuum against the venturi tube and continue to work when it ingests some oil and water. 6) Fittings must be made vacuum tight (by use of O-rings) to prevent leakage of air into the system. The system is fully automatic, and can be allowed to remain in operation with very little monitoring. It is capable of reducing the air content of the oil from 11 to less than 1 volume percent in about 4 hours and to keep the water content below 100 parts per million.

Anderson, Christopher W.↗
NASA NTRS2010

Detection of Natural Oil Seeps in the Atlantic Ocean Using MODIS

Natural oil seepage is the release of crude oil into the ocean from fissures in the seabed. Oil seepage is a major contributor to the total amount of oil entering the world s oceans. According to a 2003 study by the National Academy of Sciences (NAS), 47 percent of oil entering the world s oceans is from natural seeps, and 53 percent is from human sources (extraction, transportation, and consumption). Oil seeps cause smooth oil slicks to form on the water s surface. Oil seeps can indicate the location of stores of fossil fuel beneath the ocean floor. Knowledge of the effect of oil seepage on marine life and marine ecosystems remains limited. In the past, remote sensing has been used to detect oil seeps in the Gulf of Mexico and off of the coast of southern California. This project utilized sun glint MODIS imagery to locate oil slicks off of the Atlantic coast, an area that had not previously been surveyed for natural oil seeps using remote sensing. Since 1982, the Atlantic Ocean has been closed to any oil and gas drilling. Recently, however, the U.S. Minerals Management Services (MMS) has proposed a lease for oil and gas drilling off the coasts of Virginia and North Carolina. Determining the location of seepage sites in the Atlantic Ocean will help MMS locate potential deposits of oil and natural gas, thereby reducing the risk of leasing areas for petroleum extraction that do not contain these natural resources.

Reahard, Ross↗
NASA NTRS1984

The influence of temperature on the lubricating effectiveness of MoS2 dispersed in mineral oils

The effects of oil viscosity, base oil temperature, and surface-active agents naturally present in mineral oils on the lubricating effectiveness of MoS2 dispersions under boundary lubrication conditions are investigated. Friction and wear data are obtained from tests conducted under a wide range of oil viscosities and operating temperatures. The dispersion temperature at which the friction dropped below that obtained with the base oils, depended upon the base oil viscosity and the concentration of surface-active agents present in the oil. White oils showed reductions in friction before mineral oils of like viscosity, and lower viscosity oils showed reductions in friction before heavier viscosity oils. The results show that for a given base oil, wear increases as temperature increases, while the wear obtained from a MoS2 dispersion made from the base oil remains approximately constant as temperature is increased.

Rolek, R. J.↗
NASA NTRS2011

Gulf of Mexico Air Quality: CALIPSO Support for Gulf of Mexico Air Quality Relating to the Deepwater Horizon Oil Spill

On April 20, 2010, an oil platform belonging to BP exploded and leaked a huge volume of oil into the Gulf of Mexico. In an effort to control the spread of the oil, BP applied dispersants such as Corexit and conducted in-situ burnings of the oil. This catastrophe created a complex chain of events that affected not only the fragile water and land ecosystems, but the humans who breathe the air every day. Thousands of people were exposed to fumes associated with oil vapors from the spill, burning of the oil, and the toxic mixture of dispersants. While aiding in clean-up efforts, local fishermen were directly exposure to fumes when working on the Gulf. A notable amount of Gulf Coast residents were also exposed to the oil fumes as seasonal southeasterly winds blew vapors toward land. The Volatile Organic Compounds (VOC) found in oil vapors include: benzene, toluene, ethyl benzene, xylene, naphthalene, hydrogen sulfide and particulate matter (PM). Increases in water temperature and sunlight due to the summer season allow for these VOCs and PM to evaporate into the air more rapidly. Aside from the VOCs found in oil vapors, the dispersant being used to break up the oil is highly toxic and is thought to be even more toxic than the oil itself (EPA website, 2010). To protect human health, the environment, and to make informed policy decisions relevant to the spill, the EPA Region 6 has continuously monitored the affected areas carefully for levels of pollutants in the outdoor air that are associated with petroleum products and the burning of oil along the coast. In an effort to prevent, prepare for, and respond to future oil spills that occur in and around inland waters of the United States, the EPA has been working with local, state, and federal response partners. Air quality measurements were collected by the EPA at five active monitoring systems stationed along the coast.

Nguyen, Myngoc T.↗
NASA NTRS2021

Oil Spill Thickness Determination from L-band Synthetic Aperture Radar

Efficient and effective oil spill response requires accurate information regarding slick location, extent, and thickness to direct remediation activities. Of these three, the most challenging to determine is thickness. Ideally, the needed information would be provided by remote sensing instruments, particularly those operating from space. In this study we consider the capability of L-band synthetic aperture radar (SAR) for identifying oil layer thickness for slicks in open water given the range of oil properties and environmental conditions typical in this setting. The goal is to determine layer thickness with precision equivalent to that of the Bonn Agreement Oil Appearance Code. Here we report preliminary results of an ongoing study to determine whether either relative or absolute slick thickness can be determined from L-band SAR. The study has an experimental component, which uses low noise airborne SAR data acquired over slicks to evaluate the capability to determine relative thickness, i.e., to differentiate sheen from zones of varying thicker oil within a slick. The component of the study to evaluate whether absolute thickness can be determined from SAR uses backscatter simulations within a physics- based model of electromagnetic scattering from slicked and unslicked ocean surfaces accounting for oil properties, meteorological conditions, and sea state. As part of the theoretical component of the study, we evaluate the backscatter sensitivity to oil characteristics to determine which properties most influenced the SAR measurements. These results are used to determine whether the oil-to-water ratio or the oil thickness can be quantified with reasonable accuracy based upon SAR backscatter intensities alone or whether it requires calibration to go from relative to absolute thickness. The ratio of the backscatter contrast between clean and slicked ocean surfaces is shown to be sensitive to variations within slicks that well correlate with the oil layer thickness. Determination of absolute thickness is much more challenging given the variation of oil properties as the oil weathers on the sea surface.

Holt, Benjamin↗
NASA NTRS1950

Rise of Air Bubbles in Aircraft Lubricating Oils

Lubricating and antifoaming additives in aircraft lubricating oils may impede the escape of small bubbles from the oil by forming shells of liquid with a quasi-solid or gel structure around the bubbles. The rates of rise of small air bubbles, up to 2 millimeters in diameter, were measured at room temperature in an undoped oil, in the same oil containing foam inhibitors, and in an oil containing lubricating additives. The apparent diameter of the air bubbles was measured visually through an ocular micrometer on a traveling telescope. The bubbles in the undoped oil obeyed Stokes' Law, the rate of rise being proportional to the square of the apparent diameter and inversely proportional to the viscosity of the oil. The bubbles in the oils containing lubricating additives or foam inhibitors rose more slowly than the rate predicted by Stokes 1 Law from the apparent diameter, and the rate of rise decreased as the length of path the bubbles traveled increased. A method is derived to calculate the thickness of the liquid shell which would have to move with the bubbles in the doped oils to account for the abnoi'I!l8.lly slow velocity. The maximum thickness of this shell, calculated from the velocities observed, was equal to the bubble radius.

LUBRICATING OILS - FOAMING↗
NASA NTRS1939

Compression-ignition engine performance with undoped and doped fuel oils and alcohol mixtures

Several fuel oils, doped fuel oils, and mixtures of alcohol and fuel oil were tested in a high-speed, single-cylinder, compression-ignition engine to determine power output, fuel consumption, and ignition and combustion characteristics. Fuel oils or doped fuel oils of high octane number had shorter ignition lags, lower rates of pressure rise, and gave smoother engine operation than fuel oils or doped fuel oils of low octane number. Higher engine rotative speeds and boost pressures resulted in smoother engine operation and permitted the use of fuel oils of relatively low octane number. Although the addition of a dope to a fuel oil decreased the ignition lag and the rate of pressure rise, the ensuing rate of combustion was somewhat slower than for the undoped fuel oil so that the effectiveness of combustion was practically unchanged. Alcohol used as an auxiliary fuel, either as a mixture or by separate injection, increased the rates of pressure rise and induced roughness. In general, the power output decreased as the proportion of alcohol increased and, below maximum power, varied with the heating value of the total fuel charge.

Moore, Charles S↗
NASA NTRS1946

Altitude-Wind-Tunnel Investigation of Oil-System Performance of XR-4360-8 Engine in XTB2D-1 Airplane

An investigation was conducted in the Cleveland altitude wind tunnel to determine the aerodynamic characteristics and the oil delivery critical altitude of the oil-cooler installation of an XTB2D-1 airplane. The investigation was made with the propeller removed end with the engine operating at 1800 brake horsepower, an altitude of 15,000 feet (except for tests of oil-delivery critical altitude), oil-cooler flap deflections from -20 degrees to 20 degrees and inclinations of the thrust axis of 0 degrees, 1.5 degrees, and 6 degrees. At an inclination of the thrust axis of 0 degrees and with the propeller operating, the total-pressure recovery coefficient at the face of the oil cooler varied from 0.84 to 1.10 depending on the flap deflection. With the propeller removed, the best pressure recovery at the face of the oil cooler was obtained at an inclination of the thrust axis of 1.5 degrees. Air-flow separation occurred on the inner surface of the upper lip of the oil-cooler duct inlet at an inclination of the thrust axis of 0 degrees and on the inner surface of the lower lip at 6 degrees. Static pressure coefficients over the duct lips were sufficiently low that no trouble from compressibility would be encountered in level flight. The oil-delivery critical altitude at cruising power (2230 rpm, 1675 bhp) was approximately 18,500 feet for the oil system tested.

Conrad, E. William↗
NASA NTRS2014

Crude Oil Remote Sensing, Characterization and Cleaning with CW and Pulsed Lasers

For detection, identification and characterization of crude oil we combine several optical methods of remote sensing of crude oil films and emulsions (coherent fringe projection illumination (CFP), holographic in-line interferometry (HILI), and laser induced fluorescence). These methods allow the three-dimensional characterization of oil spills, important for practical applications. Combined methods of CFP and HILI are described in the frame of coherent superposition of partial interference patterns. It is shown, that in addition to detection/identification laser illumination in the green-blue region can also degrade oil slicks. Different types of surfaces contaminated by oil spills are tested: oil on the water, oil on the flat solid surfaces and oil on the curved surfaces of pipes. For the detection and monitoring of the laser-induced oil degradation in pipes, coherent fiber bundles were used. Both continuous-wave (CW) and pulsed lasers are tested using pump-probe schemes. This finding suggests that properly structured laser clean-up can be an alternative environmentally-friendly method of decontamination, as compared to the currently used chemical methods that are dangerous to environment.

Kukhtareva, Tatiana↗
NASA NTRS2023

Sources of Formaldehyde in U.S. Oil and Gas Production Regions

We analyzed observational and model data to study the sources of formaldehyde over oil and gas production regions and to investigate how these observations may be used to constrain oil and gas VOC emissions. The analysis of aircraft and satellite data consistently found that formaldehyde over oil and gas production regions during spring and summer is mostly formed by the photooxidation of precursor VOCs. Formaldehyde columns over the Permian basin, one of the largest oil and gas producing regions in the United States, are correlated with production locations. Formaldehyde simulations by the atmospheric chemistry and transport model WRF-Chem, which included oil and gas NOx and VOC emissions from the fuel-based oil and gas inventory, were in very good agreement with TROPOMI satellite measurements. Sensitivity studies illustrated that VOCs released from oil and gas activities are important precursors to formaldehyde, but other sources of VOCs contribute as well, and that the formation of secondary formaldehyde is highly sensitive to NOx. We also investigated the ability of the chemical mechanism used in WRF-Chem to represent formaldehyde formation from oil and gas hydrocarbons by comparing against the Master Chemical Mechanism. Further, our work provides estimates of primary formaldehyde emissions from oil and gas production activities, with per basin averages ranging from 0.07 kg h -1 to 2.2 kg h -1 in 2018. A separate estimate for natural gas flaring found that flaring emissions could contribute 5% to 12% to the total primary formaldehyde emissions for the Permian basin in 2018.

SAF↗
NASA NTRS1972

Oil pollution signatures by remote sensing.

Study of the possibility of developing an effective remote sensing system for oil pollution monitoring which would be capable of detecting oil films on water, mapping the areal extent of oil slicks, measuring slick thickness, and identifying the oil types. In the spectral regions considered (ultraviolet, visible, infrared, microwave, and radar), the signatures were sufficiently unique when compared to the background so that it was possible to detect and map oil slicks. Both microwave and radar techniques are capable of operating in adverse weather. Fluorescence techniques show promise in identifying oil types. A multispectral system will be required to detect oil, map its distribution, estimate film thickness, and characterize the oil pollutant.

Catoe, C. E.↗
NASA NTRS1982

Into Mesh Lubrication of Spur Gears with Arbitrary Offset Oil Jet. 2: for Jet Velocities Equal to or Greater than Great Velocity

An analysis was conducted for into mesh oil jet lubrication with an arbitrary offset and inclination angle from the pitch point for the case where the oil jet velocity is equal to or greater than gear pitch line velocity. Equations were developed for minimum and maximum oil jet impingement depth. The analysis also included the minimum oil jet velocity required to impinge on the gear or pinion and the optimum oil jet velocity required to obtain the best lubrication condition of maximum impingement depth and gear cooling. It was shown that the optimum oil jet velocity for best lubrication and cooling is when the oil jet velocity equals the gear pitch line velocity. When the oil jet velocity is slightly greater than the pitch line velocity the loaded side of the driven gear and the unloaded side of the pinion receive the best lubrication and cooling with slightly less impingement depth. As the jet velocity becomes much greater than the pitch line velocity the impingement depth is considerably reduced and may completely miss the pinion.

Akin, L. S.↗
NASA NTRS1992

Evaluation of an oil-debris monitoring device for use in helicopter transmissions

Experimental tests were performed on an OH-58A helicopter main-rotor transmission to evaluate an oil-debris monitoring device (ODMD). The tests were performed in the NASA 500-hp Helicopter Transmission Test Stand. Five endurance tests were run as part of a U.S. Navy/NASA/Army advanced lubricants program. The tests were run at 100 percent design speed, 117-percent design torque, and 121 C (250 F) oil inlet temperature. Each test lasted between 29 and 122 hr. The oils that were used conformed to MIL-L-23699 and DOD-L-85734 specifications. One test produced a massive sun-gear fatigue failure; another test produced a small spall on one sun-gear tooth; and a third test produced a catastrophic planet-bearing cage failure. The ODMD results were compared with oil spectroscopy results. The capability of the ODMD to detect transmission component failures was not demonstrated. Two of the five tests produced large amounts of debris. For these two tests, two separate ODMD sensors failed, possibly because of prolonged exposure to relatively high oil temperatures. One test produced a small amount of debris and was not detected by the ODMD or by oil spectroscopy. In general, the ODMD results matched the oil spectroscopy results. The ODMD results were extremely sensitive to oil temperature and flow rate.

Lewicki, David G.↗
NASA NTRS1995

Absorption of water and lubricating oils into porous nylon

Oil and water absorption from air into sintered porous nylon can be described by infiltration into the pores of the material. This process can be modeled by a diffusion-like mechanism. For water absorption, we find a formal diffusion coefficient of 1.5 x 10(exp -4)sq cm/min when the nylon is initially dry. The diffusion coefficient is 4 x 10(exp -6)sq cm/min when the nylon is oil-impregnated prior to air exposure. In a 52% RH atmosphere, dry nylon absorbs 3% w/w water, and oil-impregnated nylon absorbs 0.6% w/w water. For oil absorption there are three steps: (1) surface absorption and infiltration into (2) larger and (3) smaller pores. Surface absorption is too fast to be measured in these experiments. The diffusion coefficient for the second step is 6 x 10(exp -4)sq cm/min for SRG-60 oil into dry nylon and 4 x 10(exp -4)sq cm/min for air-equilibrated nylon. The diffusion coefficient for the third step is about 1 x 10(exp -6)sq cm/min for both cases. The total amount of oil absorbed is 31% w/w. The interaction between water and nylon is not as strong as that between water and cotton-phenolic: oil can replace water, and only a small amount of water can enter previously oil-impregnated nylon.

Bertrand, P. A.↗
NASA NTRS1997

The Role of Tribology in the Development of an Oil-Free Turbocharger

Gas-turbine-based aeropropulsion engines are technologically mature. Thus, as with any mature technology, revolutionary approaches will be needed to achieve the significant performance gains that will keep the U.S. propulsion manufacturers well ahead of foreign competition. One such approach is the development of oil-free turbomachinery utilizing advanced foil air bearings, seals, and solid lubricants. By eliminating oil-lubricated bearings and seals and supporting an engine rotor on an air film, significant improvements can be realized. For example, the entire oil system including pipes, lines, filters, cooler, and tanks could be removed, thereby saving considerable weight. Since air has no thermal decomposition temperature, engine systems could operate without excessive cooling. Also, since air bearings have no diameter-rpm fatigue limits (D-N limits), engines could be designed to operate at much higher speeds and higher density, which would result in a smaller aeropropulsion package. Because of recent advances in compliant foil air bearings and high temperature solid lubricants, these technologies can be applied to oil-free turbomachinery. In an effort to develop these technologies and to demonstrate a project along the path to an oil-free gas turbine engine, NASA has undertaken the development of an oil-free turbocharger for a heavy duty diesel engine. This turbomachine can reach 120000 rpm at a bearing temperature of 540 C (1000 F) and, in comparison to oil-lubricated bearings, can increase efficiency by 10 to 15 percent because of reduced friction. In addition, because there are no oil lubricants, there are no seal-leakage-induced emissions.

Dellacorte, Christopher↗
NASA NTRS1999

The Thin Oil Film Equation

A thin film of oil on a surface responds primarily to the wall shear stress generated on that surface by a three-dimensional flow. The oil film is also subject to wall pressure gradients, surface tension effects and gravity. The partial differential equation governing the oil film flow is shown to be related to Burgers' equation. Analytical and numerical methods for solving the thin oil film equation are presented. A direct numerical solver is developed where the wall shear stress variation on the surface is known and which solves for the oil film thickness spatial and time variation on the surface. An inverse numerical solver is also developed where the oil film thickness spatial variation over the surface at two discrete times is known and which solves for the wall shear stress variation over the test surface. A One-Time-Level inverse solver is also demonstrated. The inverse numerical solver provides a mathematically rigorous basis for an improved form of a wall shear stress instrument suitable for application to complex three-dimensional flows. To demonstrate the complexity of flows for which these oil film methods are now suitable, extensive examination is accomplished for these analytical and numerical methods as applied to a thin oil film in the vicinity of a three-dimensional saddle of separation.

Brown, James L.↗
NASA NTRS2001

Combustion Stages of a Single Heavy Oil Droplet in Microgravity

Heavy oil is a common fuel for industrial furnaces, boilers, marines and diesel engines. Previous studies showed that the combustion of heavy oil involves not only the complete burning of volatile matters but also the burn-out of coke residues. Detailed knowledge about heavy oil combustion therefore requires an understanding of the different burning stages of heavy oil droplets in the burner. This in turn, demands knowledge about the single droplet evaporation and combustion characteristics. This study measured the temperature and size histories of heavy oil (C glass) droplets burning in microgravity to elucidate the various stages that occur during combustion. The elimination of the gravity-induced gas convection in microgravity allows the droplet combustion to be studied in greater detail. Noting that the compositions of heavy oil are various, we also tested the fuel blends of a diesel light oil (LO) and a heavy oil residue (HOR).

Ikegami, M.↗