Using Computational Fluid Dynamics (CFD)

In most cases, we head right to our spray labs to characterize sprays and predict spray performance. We simulate our customers’ operating environments to determine the impact of many variables – air flow, temperature, pressure changes, nozzle positioning, fluid type/density, materials of construction and more – on spray performance.

However, some spray operations cannot be replicated in our labs. While we can spray solutions other than water, there are some gases and liquids that are not safe to use during testing. Plus, it is not always feasible to reproduce some mixing conditions and chemical reactions.

That’s when we rely on our extensive library of proprietary spray characterization data and CFD.

We use CFD to predict:

• Liquid and gas flow in scrubbers, towers, ducts and dryers
• Internal flow characteristics in spray nozzles
• Gas and liquid mixing in two-fluid nozzles
• Wall impact and shadowing

CFD models illustrate flow patterns, velocity, temperature, gas/liquid distributions, droplet trajectories, pressures within the entire system and impact forces and stress caused by liquid flow.

How Our Approach to CFD Modeling
is Different and Better

Standard CFD models use theoretical numeric codes that require extensive user time commitments and computational resources. Users must compile and prepare a wide variety of specific information – often requiring weeks of work.

Once the data is input into the CFD modeling program, the computational work begins. The computation time will be dependent on the complexity of the model. Standard desktop computers can be used, however, computations can take weeks to complete.

Our custom CFD models use data we’ve collected in our spray labs – which offers many benefits:

• Shorter time requirements for data preparation and entry.
• Using estimated data increases the error factor in CFD modeling.
• Using actual drop size and velocity data collected in our labs reduces the model error factor.

Problem-Solving with CFD

Gas conditioning in a cooling tower
Wetting caused by flashing in reaction column
 

Sample CFD Simulations

Evaporating Spray Inside Vertical Cooling Tower

This animation (5.1mb) was used to determine the performance of FloMax® air atomizing nozzles in a flue gas cooling application. Still images of gas velocity at the tower’s mid-plane and velocity path lines are shown first, followed by particle tracing with particle velocity magnitude scale.

Still images of gas temperature at tower’s mid-plane and temperature path lines are shown in this animation (5.1mb) followed by particle tracing with drop size scale.

Cooling of Gas with Ash Particles in an Emergency Cooling Duct (3.0mb)

Animation shows performance of a SpiralJet® nozzle in a flue gas cooling application. The ash particle tracing is shown in an isometric view.  

The second animation (3.21mb) shows a front view of the ash particle tracing with ash particle velocity magnitude scale.

The third animation (3.02mb) shows an isometric view of the ash particle tracing with ash particle velocity magnitude scale.

Spraying Water at High Pressure into Air with Full Cone Nozzle (7.14mb)

This animation shows the midline contours of spray concentration

Spraying Water at Low Pressure into Air with Full Cone Nozzle (3.24mb)

The animation shows particle tracing with encoded drop size.

Gas Cooling in a Horizontal Duct with Minimal Wall Wetting (1.41mb)

The animation shows multi-view particle tracking with encoded drop size of FloMax® air atomizing nozzles. Complete evaporation takes place just before the vertical duct turn.