43
© Springer Nature Switzerland AG 2020
S. A. Murawski et al. (eds.), Deep Oil Spills,
https://doi.org/10.1007/978-3-030-11605-7_4
Chapter 4
Jet Formation at the Spill Site
and Resulting Droplet Size Distributions
Karen Malone, Zachary M. Aman, Simeon Pesch, Michael Schlüter,
and Dieter Krause
Abstract The size distribution of oil droplets and gas bubbles forming at the exit
geometry of a deep-sea blowout is one of the key parameters to understand its propagation and fate in the ocean, whether with regard to rising time to the surface, drift
by ocean currents, dissolution or biodegradation. While a large 8 mm droplet might
rise to the sea surface within minutes or hours, microdroplets <100 μm may take
weeks or months to surface, if at all. On the other hand, a microdroplet or bubble
dissolutes faster due to its larger surface to volume ratio and is also more available
for biodegrading bacteria. To be able to properly model these effects, it is necessary
to understand the drop formation processes near the discharge point and to predict
the evolving droplet size distribution (DSD) for the specific conditions.
In this chapter, the general breakup mechanisms and flow regimes of an oil-inwater jet are discussed in Sect. 4.1. Section 4.2 focuses on the different approaches
to determine the DSD in the laboratory and field settings and critically reviews the
existing datasets. State-of-the-art models for the prediction of the DSD of a subsea
oil discharge are presented alongside a new approach based on the turbulent kinetic
energy (TKE) in Sect. 4.3, while Sect. 4.4 takes a closer look at the specific effects
of the deep sea on the DSD. Based on this, Sect. 4.5 discusses the advantages and
limitations of subsea dispersant injection. Section 4.6 provides a summary of the
chapter and gives an outlook to unresolved questions.
K. Malone (*) · D. Krause
Hamburg University of Technology, Institute of Product Development and Mechanical
Engineering Design, Hamburg, Germany
e-mail: karen.malone@tuhh.de; krause@tuhh.de
Z. M. Aman
University of Western Australia, Department of Chemical Engineering, Perth, WA, Australia
e-mail: zachary.aman@uwa.edu.au
S. Pesch · M. Schlüter
Hamburg University of Technology, Institute of Multiphase Flows, Hamburg, Germany
e-mail: simeon.pesch@tuhh.de; michael.schluter@tuhh.de
© Springer Nature Switzerland AG 2020
S. A. Murawski et al. (eds.), Deep Oil Spills,
https://doi.org/10.1007/978-3-030-11605-7_4
Chapter 4
Jet Formation at the Spill Site
and Resulting Droplet Size Distributions
Karen Malone, Zachary M. Aman, Simeon Pesch, Michael Schlüter,
and Dieter Krause
Abstract The size distribution of oil droplets and gas bubbles forming at the exit
geometry of a deep-sea blowout is one of the key parameters to understand its propagation and fate in the ocean, whether with regard to rising time to the surface, drift
by ocean currents, dissolution or biodegradation. While a large 8 mm droplet might
rise to the sea surface within minutes or hours, microdroplets <100 μm may take
weeks or months to surface, if at all. On the other hand, a microdroplet or bubble
dissolutes faster due to its larger surface to volume ratio and is also more available
for biodegrading bacteria. To be able to properly model these effects, it is necessary
to understand the drop formation processes near the discharge point and to predict
the evolving droplet size distribution (DSD) for the specific conditions.
In this chapter, the general breakup mechanisms and flow regimes of an oil-inwater jet are discussed in Sect. 4.1. Section 4.2 focuses on the different approaches
to determine the DSD in the laboratory and field settings and critically reviews the
existing datasets. State-of-the-art models for the prediction of the DSD of a subsea
oil discharge are presented alongside a new approach based on the turbulent kinetic
energy (TKE) in Sect. 4.3, while Sect. 4.4 takes a closer look at the specific effects
of the deep sea on the DSD. Based on this, Sect. 4.5 discusses the advantages and
limitations of subsea dispersant injection. Section 4.6 provides a summary of the
chapter and gives an outlook to unresolved questions.
K. Malone (*) · D. Krause
Hamburg University of Technology, Institute of Product Development and Mechanical
Engineering Design, Hamburg, Germany
e-mail: karen.malone@tuhh.de; krause@tuhh.de
Z. M. Aman
University of Western Australia, Department of Chemical Engineering, Perth, WA, Australia
e-mail: zachary.aman@uwa.edu.au
S. Pesch · M. Schlüter
Hamburg University of Technology, Institute of Multiphase Flows, Hamburg, Germany
e-mail: simeon.pesch@tuhh.de; michael.schluter@tuhh.de