DARPA’s DRAG program plans to revolutionize naval efficiency in turbulent waters

The journey of ships and undersea vehicles through oceans is fraught with challenges. One such hurdle is the resistance they encounter while cruising through water, commonly known as drag. Addressing this issue, DARPA‘s DRAG program, Drag Reducing Architected Geometries (DRAG), sets forth on a new mission to lessen this obstacle and potentially revolutionize maritime travel.

“For naval vehicles you either need more power or less drag to go farther. The problem with adding power is that it means you need more batteries, fuel, or a bigger engine, which increases the size of your ship or UUV, adding more drag. We aim to lower the drag coefficient to allow increased speed without increasing power or to go the same speed using less power.”

Dr. Susan Swithenbank, program manager in DARPA’s Defense Sciences Office

The vision behind DARPA’s DRAG program

The DRAG program is specially designed to mitigate the effects of drag on ships and uncrewed underwater vehicles (UUVs) in transitional and fully turbulent water conditions. By optimizing the shape and surface characteristics of hulls, the program aims to boost the vessels’ speed and endurance.

Transition from laminar to turbulent flow: The challenge DARPA’s DRAG program tackles

Water resistance increases as the water flow changes from laminar, where the water moves smoothly in neat layers, to turbulent, characterized by chaotic and unpredictable water movements. The DRAG program aims to tackle this transition and the high drag coefficient that results.

How DARPA’s DRAG program surpasses previous research

Previous efforts in naval engineering have focused mainly on reducing drag in laminar flow conditions. However, the DRAG program, armed with new modeling tools, sets its sights on solving the problem even in turbulent conditions.

Not just another hull design

The initiative is not focused on developing new materials for hulls or scaling up manufacturing processes. Instead, it looks at the science behind the interaction between the hull and water to develop new geometries that reduce drag.

The developmental phases of DRAG

The DRAG program from DARPA is divided into two key phases. The initial nine months focus on developing modeling and simulation tools. This is followed by a second phase aimed at devising and testing an optimal three-dimensional surface solution.

• Focus: DARPA’s DRAG Program aims to reduce drag in transitional and turbulent water conditions
• Approach: Optimizes hull shapes and surface characteristics
• Exclusions: Not focused on new hull materials or manufacturing scale-up
• Duration: 18 months in two phases (9 months each for modeling and simulation, followed by development and testing)
• Part of a larger initiative: DRAG is part of DARPA’s Disruptioneering effort designed to rapidly explore bold, high-risk ideas with the goal of accelerating scientific discovery.

The long-term impact of DARPA’s DRAG program

Though still in its early stages, the success of DARPA’s DRAG program could redefine the paradigms of naval architecture. The initiative has the potential to significantly cut fuel costs and reduce emissions, pointing towards a more sustainable and efficient future for maritime transport.