Modelling, Control and Applications of Hydrodynamic Cavitation Phenomena

Project Information

CaviPRO

Grant agreement ID: 101113564

DOI

10.3030/101113564

EC signature date 24 May 2023

Start date 1 February 2024

End date 31 January 2028

Funded under

• Marie Skłodowska-Curie Actions (MSCA)

Total cost

No data

EU contribution

€ 2 164 852,80

Coordinated by

UNIVERSITY OF LIMERICK
Ireland

Periodic Reporting for period 1 - CaviPRO (Modelling, Control and Applications of Hydrodynamic Cavitation Phenomena)

Reporting period: 2024-02-01 to 2026-01-31

Summary of the context and overall objectives of the project

The manufacturing industry faces big challenges in rising raw material costs, depleting feed stocks, and reducing environmental impact. Europe has set the goal of doubling its resource productivity by 2030 and of becoming the first climate-neutral continent by 2050 (EU 2030 climate and energy framework and 2050 long-term strategy). CaviPRO aims to harness hydrodynamic cavitation (HC) for realising the desired next-generation, intensified processes and products. Despite decades of laboratory research, the potential of HC remains largely unfulfilled because engineers cannot yet reliably control the number, intensity and location of cavitation events, and current HC devices suffer from rapid erosion and clogging.

The CaviPRO network is designed to overcome these challenges and develop new knowledge, methods, models & data for realising innovative HC devices and substantial productivity enhancements in key sectors (water, healthcare, chemicals and energy). CaviPRO addresses these barriers through four research objectives: (1) developing new quantitative understanding of cavity dynamics with 30% better spatio-temporal resolution than the state of the art; (2) researching physico-chemical transformations including pollutant degradation, crystal engineering, green organic reactions and biomass pre-treatment; (3) creating multi-scale models linking cavity-scale physics to device-scale performance; and (4) demonstrating four bench-scale applications — water treatment with 30% lower energy consumption, cavi-crystallisation producing 30% smaller crystals, organic reactions in water with 20% enhanced rates, and biomass valorisation with 20% improved potential. CaviPRO will replace current empirical design methods that are expensive, sub-optimal and often unsuccessful by validated multi-scale models for realising the hitherto unfulfilled potential of HC.

Scientifically, CaviPRO targets at least 30 high-quality open-access publications and four new experimental methods. Economically, the project aims at multiple patent applications and industrial innovations with partners including Air Liquide, Pfizer, Andritz and Biocore, and the creation of a new market segment for HC devices. Societally, CaviPRO outcomes directly address EU Green Deal objectives, UN SDGs 6, 8 and 9, and provide evidence to support EU policymaking on clean water, sustainable manufacturing, and renewable energy.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

During the first reporting period (M1–M24), the CaviPRO consortium fully achieved all planned objectives. All 10 Doctoral Candidates were recruited on schedule, enrolled in PhD programmes, and are conducting research in line with the Description of Action. All 15 deliverables and 12 milestones due during the period were completed on time.

In WP2 (Micro/Meso-Scale Cavitation), DC1 developed the first methodology to separately quantify dissolved versus undissolved gas effects on cavitation inception, showing that undissolved microbubbles shift inception pressure by 15–30% and reduce acoustic field amplitude by ~30%. DC2 identified the virtual mass coefficient gradient as a physics-based indicator of jetting regimes during bubble collapse near walls via Direct Numerical Simulation, defining three distinct regimes. DC3 completed the micro-scale characterisation of crystal breakage mechanisms under ultrasound treatment.

In WP3 (Applications), DC4 established baseline degradation kinetics for five EU-relevant micropollutants using combined HC-ozone systems. DC5 produced three publications on HC-enhanced pharmaceutical crystallisation, demonstrating zero encrustation in continuous operation. DC6 established that cavitation primarily intensifies interfacial mass transfer rather than altering reaction mechanisms. DC7 conducted extensive parametric studies of HC-based biomass pretreatment across multiple waste streams.

In WP4 (Device Performance), DC8 developed and validated a CFD framework across three device geometries. DC9 built a multi-technique experimental platform combining X-ray tomography, pressure sensing, and a novel electrochemical OH-radical dosimetry method. DC10 established fundamental scaling relationships across three orders of magnitude of device throat diameter, demonstrating that geometric scale-up leads to diminished cavitation performance.

Key scientific highlights include the first systematic quantification of dissolved versus undissolved gas effects on cavitation inception (DC1, published in Ultrasonics Sonochemistry); identification of the virtual mass coefficient gradient as a robust indicator of jetting regimes during bubble collapse (DC2); the first-ever application of hydrodynamic cavitation to enhance nucleation in pharmaceutical crystallization (DC5, three publications); development of a novel electrochemical OH-radical dosimetry method with millisecond resolution (DC9); and a definitive demonstration that geometrically similar scale-up of vortex devices leads to diminished cavitation performance, redirecting industrial strategy toward scale-out approaches (DC10).

The training programme has been delivered as designed, with two major network-wide events (Induction School at UL, September 2024; Training School 1 at TUD, March 2025), extensive local training, and a comprehensive range of transferable skills activities. Governance structures are functioning effectively, project management is robust, and all partners are contributing as planned. The DC cohort comprises 2 female and 8 male researchers representing 10 different nationalities. No significant deviations from the Description of Action have occurred. The project is fully on track to achieve all remaining objectives within the planned timeline and budget. Three inter-sectoral secondments were completed (DC4 at HZDR, DC8 at ULJ, DC9 at Paques Global B.V.) each generating tangible research outputs. Six peer-reviewed Open Access publications were produced with four additional manuscripts in preparation or under review.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

CaviPRO has generated results advancing the state of the art in HC and its industrial application. The first systematic quantification of dissolved and undissolved gas effects on inception established that experiments without gas content control are inherently unreliable, redefining best practice. The associated bubble detection methodology has potential IP value. The identification of the virtual mass coefficient gradient as a predictive indicator for jetting regimes provides a criterion integrable into engineering-scale models without full DNS resolution. New understanding of particle-bubble interactions and breakage mechanisms extends the knowledge base for processes involving suspended solids. In applications, the first-ever use of HC to enhance pharmaceutical crystallisation nucleation opens the field of "cavi-crystallisation," where encrustation elimination and doubled process longevity address persistent manufacturing bottlenecks. The demonstration that cavitation primarily intensifies interfacial mass transfer provides a critical design rule for multiphase reactor scale-up. Quantitative evidence that HC is most beneficial for structurally resistant lignocellulosic biomass establishes clear application boundaries for valorisation. At device scale, a validated CFD framework spanning three geometries and three orders of magnitude in throat diameter provides the first comprehensive simulation toolkit for HC device design. A novel electrochemical dosimetry method enabling millisecond-resolution radical detection is a breakthrough applicable beyond HC. The proof that geometric scale-up leads to diminished cavitation performance redirects strategy toward scale-out, while novel insert designs offer improved efficiency. To ensure uptake, further research on closure models linking micro- to device-scale physics, access to pilot-scale facilities, IPR protection of novel methodologies, and engagement with regulatory frameworks for water treatment and pharmaceutical manufacturing will be essential.