title: Measuring particle concentration in multiphase pipe flow using acoustic backscatter: generalization of the dual-frequency inversion method.
abstract: A technique that is an extension of an earlier approach for marine sediments is presented for determining the acoustic attenuation and backscattering coefficients of suspensions of particles of arbitrary materials of general engineering interest. It is necessary to know these coefficients (published values of which exist for quartz sand only) in order to implement an ultrasonic dual-frequency inversion method, in which the backscattered signals received by transducers operating at two frequencies in the megahertz range are used to determine the concentration profile in suspensions of solid particles in a carrier fluid. To demonstrate the application of this dual-frequency method to engineering flows, particle concentration profiles are calculated in turbulent, horizontal pipe flow. The observed trends in the measured attenuation and backscatter coefficients, which are compared to estimates based on the available quartz sand data, and the resulting concentration profiles, demonstrate that this method has potential for measuring the settling and segregation behavior of real suspensions and slurries in a range of applications, such as the nuclear and minerals processing industries, and is able to distinguish between homogeneous, heterogeneous, and bed-forming flow regimes.
authors.affiliation: School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Hugh P
authors.initials: HP
authors.lastname: Rice
authors.affiliation: School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Fairweather
authors.affiliation: School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Timothy N
authors.initials: TN
authors.lastname: Hunter
authors.affiliation: School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Bashar
authors.initials: B
authors.lastname: Mahmoud
authors.affiliation: School of Process, Environmental and Materials Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Simon
authors.initials: S
authors.lastname: Biggs
authors.affiliation: School of Earth and Environment, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Jeff
authors.initials: J
authors.lastname: Peakall