Newton’s momentum principles could help design safer offshore facilities in extreme waves

Researchers have developed a novel model to accurately and efficiently predict the impact of “green water”—water washing onto the deck of an offshore facility during extreme wave conditions.

Transforming Energy Infrastructure through Digital Engineering (TIDE) researchers at The University of Western Australia developed the model for floating production, storage and offloading (FPSO) facilities, which house essential components for hydrocarbon processing.

They include separation systems, water treatment, gas compression equipment, power generation, heating, ventilation and air conditioning systems, control rooms and living spaces.

As part of a plan to optimize hull size and deck layout, industry partners collaborated with TIDE to better understand wave overtopping and resulting green water loading on topside modules and equipment located on the deck, ensuring safer and more efficient design.

TIDE researchers conducted tests in UWA’s wave flume, using scale models of an FPSO and its topside modules to recreate extreme wave events and measure how water overtops the vessel and impacts the structures. This allowed them to identify the largest green water forces that occur. The research was published in 2025 in the Journal of Fluid Mechanics.

A simpler way to predict impact

TIDE Ph.D. graduate Dr. Min Gao used these experiments and advanced computational fluid dynamics to investigate green water loading on differently shaped structures.

Following advice from his supervisor, Emeritus Professor Paul H. Taylor, Gao found a simpler method based on Newton’s principles of conservation of momentum that can accurately predict forces resulting from shallow, high-speed flows such as green water overtopping.

Written more than 300 years ago, Newtonian momentum theory has previously been shown to be useful for fluid flows in hypersonic aerodynamics but had not been successfully applied to hydrodynamics.

“This finding enabled me to develop an analytical model whereby the impact of the load on topside structures can be accurately estimated using only information on the undisturbed on-deck flow, no matter where components are placed,” Gao said.

Safer layouts and broader uses

Gao’s findings have the potential to enable faster, easier estimates of green water loads for offshore design and allow TIDE industry partners to iterate and optimize hull size and layouts.

Professor Scott Draper, co-deputy director of the TIDE hub, said previous analytical modeling methods have been approximate, but Gao’s method was more precise.

“This accuracy supports the design of safer, more cost-effective offshore facilities,” Draper said.

Adjunct Associate Professor James Whelan, from UWA’s School of Engineering, said Gao had identified a simpler model that enhanced understanding and the ability to predict loads.

“We wanted to ensure that reducing our FPSO hull size didn’t equate to reduced safety for people and the environment by compromising structural reliability,” Whelan said.

“The research undertaken by TIDE, through Gao’s Ph.D., has materially improved our understanding of green water loading on topside modules, which can now be explored for inclusion in industry standards.”

Applications of the research extend beyond offshore structures, with further benefits to be realized, such as understanding potential damage to coastal structures during tropical storms.

“The industry-research relationship we’ve built has forged a trust that enables both parties to have transparency and leads to better outcomes and greater impact—we know what the design challenges are and can use this knowledge to deliver relevant research programs and outputs,” Draper said.

Who’s behind this story?

Sadie Harley

BSc Life Sciences & Ecology. Microbiology lab background with pharmaceutical news experience in oil, gas, and renewable industries.

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Robert Egan

Bachelor’s in mathematical biology, Master’s in creative writing. Well-traveled with unique perspectives on science and language.

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