High Shear Rate Viscosity of Engine Oils

Hewson, W. D.; Carey, L. R.

doi:10.4271/801394

Cited by 9 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a result, the dynamic pressure head of the fluid exiting the capillary must be subtracted from the measured pressure drop as where Q/A is the volume flow rate divided by the crosssectional area of the capillary, equivalent to the average velocity of the exiting stream, and P obs is the observed static pressure at the entrance to the channel. While in studies conducted for lower viscosity fluids, this correction has been shown to be significant; 13 the higher pressures observed in this study limit the effect of this correction to less than 2% of P obs .…”

Section: Discussionmentioning

confidence: 52%

“…In most studies it is assumed that the viscosity depends in some fashion exponentially on both pressure and temperature; see, for example, refs , , , , and 21. When the two influences are superimposed, the simplest viscosity transport relation is given by eq 2, where Δ T is the temperature rise above T 0 , α is the temperature viscosity coefficient, k p is the pressure coefficient of viscosity, P is the gauge pressure, and μ 0 is the viscosity at atmospheric pressure and temperature.…”

Section: Discussionmentioning

confidence: 99%

“…As such, this type was selected and built for this study using a Ruska Instruments high-pressure precision piston pump, which had a flow range of between 2.5 and 560 mL/h to an accuracy of ±0.02 mL/h at pressures as high as 70 MPa. The use of a piston type is preferred over a gear-type positive displacement pump, which may preshear the fluid prior to reaching the capillary, resulting in an immeasurable amount of permanent viscosity loss …”

Section: Methodsmentioning

confidence: 99%

“…The use of a piston type is preferred over a gear-type positive displacement pump, which may preshear the fluid prior to reaching the capillary, resulting in an immeasurable amount of permanent viscosity loss. 13 The capillary tubes used to make the shear viscosity measurements were all 115 µm in diameter and varied from 10.8 to 12.9 mm in length, while the temperature viscosity measurements were made using a 235 µm diameter capillary of 51.2 mm length. In general, shorter capillaries are preferred to longer ones to reduce the required pressure drop at a given flow rate.…”

Section: Polymer Characterization and Solutionmentioning

confidence: 99%

See 3 more Smart Citations

High-Shear-Rate Behavior of Radial Hydrogenated Styrene−Isoprene and Block Ethylene−Propylene Copolymer Solutions

Erickson¹,

Li²,

White³

et al. 2001

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

Using a capillary viscometry technique, the high-shear-rate behavior of two polymer additives (an ethylene−propylene block copolymer and a radial hydrogenated styrene−isoprene copolymer) in a hydrocarbon-based oil solution has been investigated. At mass concentrations of up to 2.0% for the styrene−isoprene copolymer and 1.5% for the ethylene−propylene additive, the viscosity was measured over a range of shear rates from 104 to 106 s-1. To correct for the effects of viscous heating and pressure changes, a numerical correction procedure is used which reduces the experimental results to viscosity data at a common reference temperature and pressure for comparison. Over the range of shear rates examined, the styrene−isoprene solutions exhibited typical shear-thinning behavior, becoming more dramatic at higher polymer concentrations. In addition to shear thinning at the higher shear rates, a shear-thickening region was observed in the more concentrated ethylene−propylene solutions. As the polymer concentration increased, the degree of shear thickening was shown to be more severe and the critical region was observed at lower shear rates.

show abstract

Section: Discussionmentioning

confidence: 52%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Polymer Characterization and Solutionmentioning

confidence: 99%

See 2 more Smart Citations

High-Shear-Rate Behavior of Radial Hydrogenated Styrene−Isoprene and Block Ethylene−Propylene Copolymer Solutions

Erickson¹,

Li²,

White³

et al. 2001

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…Since polymerm o d i f i e d engine oils have a shear-thinning property, viscosity measurements at working conditions are highly desirable in studying the role of viscosity in lubrication. It is estimated [1] that shear rates occurring in j o u r n a l bearings of running engines can be greater than 2× 106s-1; between piston rings and cylinder walls, shear rates can reach even 107 s -1.…”

Section: Introductionmentioning

confidence: 99%

Slit die viscometry at shear rates up to 5 � 106s?1: An analytical correction for small viscous heating errors

Lodge

1989

Rheol Acta

View full text Add to dashboard Cite

If the viscosity can be expressed in the form rl = a ( T ) f ( a ) , the walls are at a constant temperature To, and the extra stress, velocity and temperature fields are fully developed, then the wall shear rate ~)w can be calculated by applying the Weissenberg-Rabinowitsch operator to F~Q instead of to the flow rate Q, where Fc is a correction factor which differs from 1 when the temperature field is non-uniform; the isothermal equation relating the wall shear stress and pressure gradient is still valid. For the case in whcih ~7 = ~0lal n/(1 + fl(T-To)), where n, ~/0, and fl are independent of shear stress a and temperature T, an exact analytical expression for F c in terms of the NahmeGriffith number N a and n is obtained. Use of this expression gives agreement with data obtained for degassed decalin (r/= 2.5 mPa s) from a new miniature slit-die viscometer at shear rates # up to 5× 10 6 S-l; here, the correction is only 7070, Na is 1.3, and Gz, the Graetz number at the die exit, is 119. For a Cannon standard liquid $6 (~/=9mPas), agreement extends up to 5×105s-1; at 2× 106 s -~ (where Na = 7.2 and Gz = 231), the corrections are 1107o (measured) and 3607o (calculated).

show abstract

Visualization of Structural Deformation of Polymer Additives in Oil Under High Shear Flow

Kusumoto,

Kasai,

Takenaka

2024

Tribol Lett

View full text Add to dashboard Cite

High Shear Rate Viscosity of Engine Oils

Cited by 9 publications

References 12 publications

High-Shear-Rate Behavior of Radial Hydrogenated Styrene−Isoprene and Block Ethylene−Propylene Copolymer Solutions

High-Shear-Rate Behavior of Radial Hydrogenated Styrene−Isoprene and Block Ethylene−Propylene Copolymer Solutions

Slit die viscometry at shear rates up to 5 � 106s?1: An analytical correction for small viscous heating errors

Visualization of Structural Deformation of Polymer Additives in Oil Under High Shear Flow

Contact Info

Product

Resources

About