Saving energy in turbulent flows with unsteady pumping

Area of Science:

• Fluid dynamics
• Energy efficiency
• Turbulence control

Background:

• Viscous dissipation causes significant energy losses in fluid flows.
• Turbulence substantially increases friction and energy requirements for pumping in ducts.
• Current research focuses on new strategies to mitigate turbulence-induced energy losses.

Purpose of the Study:

• To propose a novel and simple drag-reduction technique for internal fluid flows.
• To achieve substantial energy savings by reducing energy losses induced by turbulence.
• To investigate the impact of temporally intermittent pumping on fluid flow dynamics.

Main Methods:

• Numerical simulations were employed to analyze fluid flow behavior.
• A temporally intermittent pumping strategy was implemented, alternating "pump on" and "pump off" phases.
• The study focused on the cyclic transition between quasi-laminar and turbulent flow states.

Main Results:

• Modulating power injection over time leads to significant energy savings.
• Intermittent pumping allows the flow to cyclically enter a quasi-laminar state during acceleration.
• The flow transitions to a turbulent state during the deceleration phase.

Conclusions:

• Temporally intermittent pumping is an effective drag-reduction technique for internal flows.
• This method offers substantial energy savings, leading to economic benefits and reduced environmental impact.
• Understanding this process can help industries reduce energy waste and harmful emissions.