Richard W. Hanks

Bio: Richard W. Hanks is an academic researcher from Brigham Young University. The author has contributed to research in topics: Reynolds number & Turbulence. The author has an hindex of 15, co-authored 30 publications receiving 615 citations.

Theoretical analysis of the turbulent flow of non‐newtonian slurries in pipes

Abstract: A theoretical model is derived which permits the analytical calculation of the friction factor-Reynolds number curves for non-Newtonian slurries flowing isothermally in smooth pipes. This model is based upon the Bingham plastic rheological equation of state. A change of mechanism in the transition phenomenon is observed to occur for N/sub He/ = 5 (10/sup 5/), where N/sub He/ is the familiar Hedstrom number. Below this value turbulence is suppressed relative to Newtonian flow, while above this value the transition is delayed but turbulence is enhanced relative to Newtonian flow. A set of theoretical design curves of friction factor versus Reynolds number covering laminar, transitional, and turbulent flows is calculated and presented for a range of N/sub He/ values from 10/sup 3/ to 10/sup 9/.

Short Fundamental Equations of State for 20 Industrial Fluids

Abstract: In a preceding project, functional forms for “short” Helmholtz energy equations of state for typical nonpolar and weakly polar fluids and for typical polar fluids were developed using simultaneous optimization. In this work, the coefficients of these short forms for the equations of state have been fitted for the fluids acetone, carbon monoxide, carbonyl sulfide, decane, hydrogen sulfide, 2-methylbutane (isopentane), 2,2-dimethylpropane (neopentane), 2-methylpentane (isohexane), krypton, nitrous oxide, nonane, sulfur dioxide, toluene, xenon, hexafluoroethane (R-116), 1,1-dichloro-1-fluoroethane (R-141b), 1-chloro-1,1-difluoroethane (R-142b), octafluoropropane (R-218), 1,1,1,3,3-pentafluoropropane (R-245fa), and fluoromethane (R-41). The 12 coefficients of the equations of state were fitted to substance specific data sets. The results show that simultaneously optimized functional forms can be applied to other fluids out of the same class of fluids for which they were optimized without significant loss of a...

Device performance and polymer morphology in polymer light emitting diodes: The control of thin film morphology and device quantum efficiency

Abstract: We present the results of a systematic study on how the processing conditions of spin casting affect the morphology of polymer thin films, and how the morphology affects polymer light-emitting diode (LED) performance. The absorption peaks of poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1, 4-phenylene vinylene) (MEH-PPV) thin films, which reflects the conjugation of π electrons, are strongly correlated to the spin-casting conditions. At high spin speed, better conjugation is observed. In addition, the photoluminescence emission peak of MEH-PPV films at ∼630 nm has a strong correlation to polymer aggregation. By proper selection of organic solvents, polymer solution concentrations, and spin speeds, we are able to control the aggregation of the polymer chains. Subsequently, we are able to control the emission color and the quantum efficiency of the MEH-PPV LEDs by simply adjusting the spin-casting conditions. Although spin casting is the most commonly used technique for the preparation of polymer thin films, our fin...

Compositions and methods for hydraulic fracturing

Abstract: A subterranean formation is treated by introducing a fracturing treatment composition comprising a polymer treatment fluid containing a dispersion of hydrophilic water swellable particles into the formation. The water swellable particles comprise synthetic polymers that are crosslinked so that they are water insoluble, but capable of swelling in the presence of relatively small amounts of water. When used with treatment fluids containing at least a small amount of water, the particles swell and reduce fluid loss to the formation during the treatment. When used during a hydraulic fracturing treatment of a hydrocarbon bearing formation, the particles may also reduce or eliminate water production following the fracturing treatment by restricting the extension of a fracture into water-bearing formations, and/or by restricting the flow of fluids from water-bearing areas.

Isothermal start-up of pipeline transporting waxy crude oil

Abstract: This paper is concerned with the start-up problem in pipeline transportation of gelled waxy crude oil after a period of shutdown. The analysis presented is based on a three-yield-stress model, which has been experimentally verified for waxy crude oil. Three possibilities of the start-up process are discussed according to the applied pressure relative to the complex yielding behaviour of the oil, which is represented by three characteristic yield stresses – an elastic-limit, a static and a dynamic yield stress. The physical model of the start-up assumes that the gelled oil is to be displaced by introducing another fluid under constant pump pressure and that the displacing fluid displays time-independent yield stress behaviour. Using rheological property data for a gelled crude oil from the North Sea and a time-dependent Bingham style equation, the flow after a successful start-up is simulated by computing changes in the oil flow rate with time, and the clearing time as function of the applied pressure and characteristics of the displacing fluid. Both laminar and turbulent flows of the two fluids are considered in the model. The results indicate that the yield stress and the time-dependent rheology of the gelled oil play an important role in determining the oil flow rate after start-up, and that the start-up computer model is highly sensitive to the rheological behaviour of the gelled oil. An appropriate method for measuring the rheological properties of waxy crude oil for this purpose is described.