33 citations · 100 across the 19 of their papers we have counts for
21 papers
Controlling three-dimensional falling liquid films: from weighted-residual models to direct numerical simulation
Oscar A. Holroyd, Susana N. Gomes, Radu Cimpeanu
We consider the problem of controlling a three-dimensional falling liquid film using same-fluid blowing and suction through the substrate. Building upon recent results for the corr…
Liquid bridges between horizontal cylinders: effects of gravity and electric fields
Agnes J. Bokányi-Tóth, Andrew J. Archer, Radu Cimpeanu +3
Liquid bridges suspended between two parallel horizontal cylinders are studied using experiments, reduced-order mathematical modelling and numerical simulations. Both non-electrifi…
Data-Driven Equation Discovery for Nonlinear Liquid Film Flows
Sebastian T. Dooley, Albert P. Bartók, James E. Sprittles +1
Over the past decade data-driven equation discovery emerged as a powerful alternative to first principles-based methodologies traditionally used in mathematical modelling cycles. T…
Fast droplet impact onto slowly moving deep pools
Thomas C. Sykes, Luke F. L. Alventosa, J. Rafael Castrejon-Pita +3
When a fast droplet impacts a pool, the resulting ejecta sheet dynamics determine the final impact outcome. At low Capillary numbers, the ejecta sheet remains separate from a deep…
Bouncing to coalescence transition for droplet impact onto moving liquid pools
Daniel M. Harris, Luke F. L. Alventosa, Oliver Sand +5
A droplet impacting a deep fluid bath is as common as rain over the ocean. If the impact is sufficiently gentle, the mediating air layer remains intact, and the droplet may rebound…
Non-linear estimators for the observation and stabilisation of falling liquid films
Oscar Holroyd, Radu Cimpeanu, Susana N. Gomes
Falling liquid films are complex physical processes modelled by infinite-dimensional dynamical systems. The interfacial behaviour is characterised by the Reynolds number, a nondime…
Drop rebound at low Weber number
Chase T. Gabbard, Elvis A. Aguero, Radu Cimpeanu +5
We study the rebound of drops impacting non-wetting substrates at low Weber number through experiment, direct numerical simulation, and reduced-order modeling. Submillimeter-s…
A simulation modeling framework for fluid motion and transport in a rocking bioreactor with application to cultivated meat production
Minki Kim, Daniel M. Harris, Radu Cimpeanu
Rocking or wave-mixed bioreactors have emerged as a promising innovation in the production of cultivated meat due to their disposable nature, low operating costs, and scalability.…
Stabilisation of falling liquid films with restricted observations
Oscar A. Holroyd, Radu Cimpeanu, Susana N. Gomes
We propose a method to stabilise a solution to equations describing the interface of thin liquid films falling under gravity with a finite number of actuators and restricted observ…
Modelling two-dimensional droplet rebound off deep fluid baths
Katie A Phillips, Radu Cimpeanu, Paul A Milewski
In order for a droplet to rebound rather than coalesce with a liquid bath, a layer of gas must persist throughout the impact. This gas, typically an air layer acts as a lubricant t…
A new flow-based design for double-lumen needles
Radu Cimpeanu, Alfonso A. Castrejon-Pita, Lee Nai Lim +2
Oocyte retrieval forms a crucial part of in vitro fertilisation treatment and its ultimate outcome. Standard double-lumen needles, which include a sequence of aspiration and flushi…
Linear quadratic regulation control for falling liquid films
Oscar A. Holroyd, Radu Cimpeanu, Susana N. Gomes
We propose and analyse a new methodology based on linear-quadratic regulation (LQR) for stabilising falling liquid films via blowing and suction at the base. LQR methods enable rap…
Inertio-capillary rebound of a droplet impacting a fluid bath
Luke F. L. Alventosa, Radu Cimpeanu, Daniel M. Harris
The rebound of droplets impacting a deep fluid bath is studied both experimentally and theoretically. Millimetric drops are generated using a piezoelectric droplet-on-demand genera…
Electrostatic control of the Navier-Stokes equations for thin films
Alexander W. Wray, Radu Cimpeanu, Susana N. Gomes
A robust control scheme is derived and tested for the Navier-Stokes equations for two-dimensional multiphase flow of a thin film underneath an inclined solid surface. Control is ex…
Capillary-scale solid rebounds: experiments, modelling and simulations
Carlos A. Galeano-Rios, Radu Cimpeanu, Isabelle A. Bauman +3
A millimetre-size superhydrophobic sphere impacting on the free surface of a quiescent bath can be propelled back into the air by capillary effects and dynamic fluid forces, whilst…
Droplet impact onto a spring-supported plate: analysis and simulations
Michael J. Negus, Matthew R. Moore, James M. Oliver +1
The high-speed impact of a droplet onto a flexible substrate is a highly nonlinear process of practical importance which poses formidable modelling challenges in the context of flu…
Active control of liquid film flows: beyond reduced-order models
Radu Cimpeanu, Susana N. Gomes, Demetrios T. Papageorgiou
The ability to robustly and efficiently control the dynamics of nonlinear systems lies at the heart of many current technological challenges, ranging from drug delivery systems to…
Deformation and dewetting of liquid films under gas jets
C. J. Ojiako, R. Cimpeanu, H. Bandulasena +2
We study the deformation and dewetting of liquid films under impinging gas jets using experimental, analytical and numerical techniques. We first derive a reduced-order model (a th…
Instability and dripping of electrified liquid films flowing down inverted substrates
Ruben J Tomlin, Radu Cimpeanu, Demetrios T Papageorgiou
We consider the gravity-driven flow of a perfect dielectric, viscous, thin liquid film, wetting a flat substrate inclined at a non-zero angle to the horizontal. The dynamics of the…
Three-dimensional high speed drop impact onto solid surfaces at arbitrary angles
Radu Cimpeanu, Demetrios T. Papageorgiou
The rich structures arising from the impingement dynamics of water drops onto solid substrates at high velocities are investigated numerically. Current methodologies in the aircraf…
Electrohydrodynamically induced mixing in immiscible multilayer flows
Radu Cimpeanu, Demetrios T. Papageorgiou
In the present study we investigate electrostatic stabilization mechanisms acting on stratified fluids. Electric fields have been shown to control and even suppress the Rayleigh-Ta…