Key Takeaways

• The device measurably reduced friction loss along the pivot lateral. Pressure increased at every measurement point, and total friction loss from the first drop to the far end of the lateral dropped from 4.9 to 4.3 psi, about 12%. 

• Pressure gains were largest at the outer spans. The first drop near the pivot gained 1.1 psi, while Towers 3 and 7 gained 1.7 to 1.8 psi. These outer spans irrigate roughly 80% of the field.

• Flow rate and energy use did not change in this system. Because every sprinkler had its own pressure regulator, the extra pressure was dissipated at the regulators rather than showing up as more water or less pump energy.

• On regulated pivots, energy savings would come from slowing the pump. Lower friction loss means the pump can deliver the same pressure at the sprinklers at a lower speed, using a variable frequency drive or throttle adjustment. We did not test this step; it is the focus of next year's trials.

• The benefit would look different on unregulated systems. On a pivot without pressure regulators, or on an end gun, the same pressure gain would translate directly into more flow rather than being dissipated by pressure regulators.

• This is a first-year, single-site, single-device evaluation. Baseline and treatment were tested on different days using two different flow meter types, which is a limitation worth keeping in mind.

Considerations for Growers

• Energy savings depend heavily on system configuration. The manufacturer has reported 30% energy savings in controlled test-line and closed-loop trials. On this pivot, every sprinkler had its own pressure regulator holding flow and pressure constant at a fixed pump speed, so the friction-loss reduction we measured stayed in the pipe as pressure rather than converting to flow or energy savings. The difference reflects how the systems were configured. See the energy-savings discussion below.

• It may be worth a look where pressure is genuinely short. Systems with declining well capacity, marginal end-gun pressure, or terminal spans running close to the regulator setpoint are situations where a pressure gain could translate into improved performance.

• Ask about pump-speed reduction, not flow increase, on regulated systems. The theoretical path to energy savings here is trimming pump speed while holding target pressure.

• Treat this as one data point, not a verdict. A single site, a single device, and two test days are a start, not a full picture. Ask about independent, multi-site data before making a purchase decision.

Background: Friction Loss and Pump Energy in Center Pivots

Pumping water is one of the largest energy costs on an irrigated farm, and a lot of that energy goes toward simply overcoming friction inside the pipe, which causes water pressure to decline as it moves through the system. U.S. irrigation consumed an estimated 60.6 terawatt-hours (TWh) of energy in 2018, including 37.5 TWh of electricity, to irrigate about 22.6 million hectares of cropland. As groundwater tables decline across parts of the High Plains Aquifer, pumping lift and the energy that goes with it keep climbing.

Most center pivots fight friction the conventional way: bigger pumps, larger pipe or lower nozzle pressure, each with its own cost or trade-off. A different approach, used in some industrial piping, is to change how the water moves inside the pipe rather than fight the friction directly. Spinning the water into a helical, corkscrew-like flow pulls the fast-moving core away from the pipe wall, which in theory reduces the drag between water and pipe.

The GS Vortex Flow Amplifier is a commercially available device built on this idea: a passive, inline unit with no moving parts and no power source, designed to induce and sustain that helical flow inside irrigation pipelines. In a controlled 1,000-foot test line, the manufacturer measured 30% energy savings at 300 gpm and 43% higher flow capacity per unit of pump power. The manufacturer also reports similar results from about two years of on-farm field use in Texas and Oregon. Until this study, no independent, peer-reviewed field evaluation had tested the device on a working center pivot or individually pressure-regulated sprinkler system.

Testing a Vortex Device on a Working Pivot

In 2025-26, a team of UNL researchers conducted a field study of a vortex device at the Eastern Nebraska Research, Extension and Education Center (ENREEC), near Mead. Researchers installed a GS Vortex Flow Amplifier on the 8-inch riser of a standard quarter-section center pivot. The system was a Valley center pivot with seven spans, drop nozzles and an individual pressure regulator at every sprinkler outlet, a common configuration in Nebraska. The end gun was disabled for all testing. The pivot draws from a groundwater well at the pivot point, with a pumping water level about 90 feet below ground surface.

Test Design

This was a paired comparison: the same pivot, same field position, same sprinklers, tested with the device installed and again with it removed. Data were collected on two dates: March 27, 2026, with the device installed, and April 13, 2026, without it. A third date, Nov. 18, 2025, was thrown out due to a leaking drain valve that skewed the flow readings. Each test ran for about three hours after a 30-minute warm-up to reach steady state.

What We Measured

We tracked system flow rate at the inlet and pressure at four points along the lateral: the first drop near the pivot, and at Towers 1, 3 and 7, the last of which sits 1,294 feet out. All pressure readings used the same gauge to rule out instrument differences. One limitation: flow rate was measured with a propeller meter under baseline conditions and a magnetic meter with the device installed because the propeller meter had to be removed to install the device. The two-meter types differ slightly in accuracy and sensitivity, which is worth keeping in mind when comparing flow numbers between the two test days.

Why Pressure Regulators Matter Here

Every sprinkler on this pivot has its own pressure regulator, which holds discharge pressure essentially constant regardless of what the mainline is doing, as long as mainline pressure stays above the regulator’s setpoint. That means, if the vortex device reduces friction loss, the extra pressure has nowhere obvious to go on this system — it gets dissipated at the regulators rather than showing up as more flow. The real test on a regulated system like this one is whether pressure along the lateral goes up, not whether flow rate does.

Results

Flow Rate and Energy Use: Unchanged, Because Regulators Absorbed the Gain

System flow rate was 621 gpm without the device and 618 gpm with it installed — a 0.5% difference, well within the uncertainty of comparing two different meter types. Energy consumption was about 1.2% higher with the device installed — also not a meaningful difference. Both results are exactly what you’d expect on a fully regulated system: with every sprinkler holding its own pressure and discharge steady, the pump ran at essentially the same operating point either way.

Pressure Along the Lateral: A Consistent, Growing Gain

This is where the device showed a measurable effect. Pressure was higher at every measurement point with the device installed. 

Near the pivot, at the first drop, pressure rose from 40.9 to 42.0 psi, a gain of 1.1 psi. 

Moving out along the lateral, the pressure gain increased: 1.5 psi at Tower 1, 1.8 psi at Tower 3, and 1.7 psi at Tower 7. 

Total friction loss along the lateral: The pressure drop from the first drop to the far end fell from 4.9 psi at baseline to 4.3 psi with the device, a reduction of about 12%.

That pattern — a small gain near the pivot that grows toward the outer spans — is what you’d expect if the device is genuinely reducing friction along the length of pipe, since friction losses accumulate with distance. The largest gains landed at Towers 3 and 7, the zone that covers roughly 80% of the field area, which is also where pivot systems typically run short on pressure to begin with.

Where Did the Pressure Gain Go?

On this system, nowhere measurable yet. Because the pressure regulators simply dissipated the extra pressure rather than passing it on as more flow, the gain didn’t show up as additional water applied or lower pump energy. The pump ran at a fixed speed throughout testing, so the pressure the device preserved stayed in the pipe rather than being converted into anything a grower would notice at the meter. That’s a property of this particular test setup, not necessarily a limit on the device itself — a system without regulators, or one where terminal pressure is genuinely short, would very likely translate the same pressure gain into a real, usable benefit.

Potential for Energy Savings Through Reduced Pump Speed

This trial ran the pump at a fixed speed throughout, so any friction loss the device saved stayed in the pipe as extra pressure rather than being converted into lower pumping energy. That’s the mechanical reason energy consumption didn’t change in this study. 

In a pressure-regulated system, reducing friction loss effectively lowers the total dynamic head — the total pressure the pump must provide — needed to hit target pressure at the sprinklers. That means a producer could, in principle, trim pump speed while still delivering the same flow and pressure, using a variable frequency drive on an electric motor, a throttle adjustment on a diesel unit or similar controls. The producer could then capture the saved friction loss as reduced energy use instead of unused head.

We did not test that step here. Also, real-world pump curves, well drawdown, variable field conditions and the practical limits of adjusting pump or engine speed in the field can all mask or reduce energy savings that appear in a controlled test.

In year II, we plan to retest the device on producer-operated systems where pump speed can be adjusted. We hope this will demonstrate whether the pressure gain measured here actually converts into lower energy use under commercial conditions and to be upfront that it may not, or may do so only partially, once those real-world factors are in play.

Where This Could Matter in Practice

A 1 to 2 psi gain sounds small, but it can matter in specific situations:

• Systems without pressure regulators. Extra pressure along the pivot lateral would translate directly into more sprinkler discharge, effectively adding system capacity without touching the pump.
• End guns. End gun performance is sensitive to inlet pressure, and even a 1 to 2 psi gain at the distal end could meaningfully extend the wetted radius, which matters most where corner coverage is already tight.
• Aging wells and worn pumps. On systems where declining well yield or pump wear has pulled pressure at the end of the pivot below design specs, recovering a couple of psi at the far end could partially restore lost coverage without a pump replacement.
• Longer laterals and higher-flow systems. Systems with more pipe and higher flow rates (more friction loss to begin with) have more room for a friction-reduction device to work with. Systems already running near the minimum flow for vortex formation may see less benefit.

One site-specific caveat: At ENREEC, the well sits right at the pivot point, so there’s very little horizontal mainline between the pump and the device. Vortex devices generally need a minimum straight run of pipe upstream to fully develop the rotational flow, and it’s not yet clear whether the vertical pump column at this site gave the device its best shot. Systems with a longer horizontal mainline between the well and the pivot — a common layout where wells are offset from the pivot point — may see stronger results.

Where This Leaves Us

In this first-year test, the GS Vortex device produced a real, physically consistent reduction in friction loss along a working center pivot lateral. Pressure went up at every measurement point compared to the baseline test, and the gain grew toward the outer spans exactly where a friction-reduction mechanism would predict. What it didn’t do on this fully regulated system is change flow rate or energy consumption, because the pressure regulators dissipated the gain before it could turn into anything measurable at the meter or the power panel.

That leaves an open, practical question: does the preserved pressure translate into pump-speed savings, better end-gun coverage or restored capacity on systems where pressure is limiting? This trial demonstrates that the underlying hydraulic effect is real. Confirming the practical payoff will require testing on those systems, ideally over more than one season.

Study Limitations

This is a first-year evaluation of one device on one pivot. Baseline and treatment conditions were tested on different days, and flow rate was measured with a propeller meter at baseline and a magnetic meter with the device installed, because the propeller meter had to be removed before the device was installed. The use of different meters primarily affects the flow comparison; all pressure readings used the same gauge. In addition, the well at ENREEC sits at the pivot point, leaving little straight horizontal pipe upstream of the device for rotational flow to fully develop. Systems with a longer mainline between the well and the pivot may perform differently. Energy savings from reduced pump speed were not tested.

Acknowledgments and Disclosures

This study was conducted in collaboration with GS Vortex Systems, which provided the device evaluated and supported the field testing. Data collection, analysis and interpretation were conducted independently by the University of Nebraska-Lincoln, and the company had no role in the decision to publish or in the conclusions drawn. Mention of trade names is for informational purposes and does not imply endorsement by UNL. Thanks to the ENREEC staff for facilitating field access and system operation, and to the technical staff and students who assisted with instrumentation and data collection.

The authors used Claude to suggest revisions to the structure and wording of this article for clarity and readability. AI tools were not used in data collection, analysis or interpretation. The authors reviewed and edited all text and are responsible for its content.

The full technical report is available on UNL Digital Commons.