Computational Fluid Dynamics: Engineering an Efficient Spray System

Computational fluid dynamics (CFD) have radically changed the way engineers are able to design more efficient nozzle technology. Referring to the way force, pressure, and distance impact the final outcome of liquid moving through a pipe, CFD data analysis gives us unique insights into what it takes to create highly efficient and complex spray systems, ensuring you have the best options for your business and your applications.

Before we get into the specifics of fluid dynamics, and why it’s so important to your nozzle selection process, let’s dive deeper into the following topics:

  • What are computational fluid dynamics?
  • How do they impact nozzle design?
  • How do we use CFD at Lechler to build the quality nozzles that have made us a top nozzle provider for over 140 years?

Read on to get started!

What is Computational Fluid Dynamics?

“Computational fluid dynamics…is a science that, with the help of digital computers, produces quantitative predictions of fluid-flow phenomena based on the conservation laws (conservation of mass, momentum, and energy) governing fluid motion.”[1]

In layman’s terms, this means that the force, pressure, and distance needed to pump fluid through a straight pipe can be calculated with extreme accuracy. However, what happens when you need more than a traditional straight pipe design? Can fluid dynamics be applied in instances when steam and other hot gases are needed to be pumped through a series of pipes?

There is also the matter of the pipe size and distance the fluid needs to travel to arrive at the intended destination. These types of calculations require special software to discover how fluid and fluid-like substances will flow differently through different systems.

About CFD Software

In a CFD software analysis, the flow of fluid is examined in relation to the physical properties of the fluid, such as velocity, pressure, temperature, density, and viscosity. “To virtually generate an accurate solution for a physical phenomenon associated with fluid flow, those properties have to be considered simultaneously.” [2]

Advantages of Computational Fluid Dynamics Usage

As we mentioned above, if you only need a simple calculation such as a straight stretch of piping, then the flow process and calculation are going to be relatively simple to work out. However, if your spray system design requires even a slight curvature, then you will likely need to use computational fluid dynamic software. Tricky curved pipes, pipes with angles, and ascending flow pipes are situations where computational fluid dynamics is a must.

Our goal with any spray system design is to produce maximum efficiency with minimum resources. One way we do this is by providing you a great selection of nozzles, more control over liquid distribution, water droplet sizes, pumps, compressors, influx, and outflow. This technology (made possible by CFD) puts you in the driver’s seat of your spray system development and saves time and money on the back end by ensuring efficiency.

 Other benefits you receive as a result of computational fluid dynamics at work:

-       You get a front row seat to the identification of spray system optimization potentials.

-       You are able to view a virtual evaluation of individual measures.

-       You benefit from risk-free virtual tests like this.

-       You save time, energy, and money by expediting your design process.

-       You receive a clear amortization analysis. [5]

How Does CFD Impact Nozzle Design?

The concept of CFD is not new, and some historians tie the origins to the original study of aerodynamics and racecars. Since 1981, computational fluid dynamics has been a growing essential in the spray nozzle industry because of the direct correlation between CFD applications and fluid flow projects. 

For instance, at Lechler USA we use CFD to help us achieve maximum efficiency in our spray systems while keeping resource use to a minimum. The data we obtain on performance allows us to reduce energy consumption of the system, the number of nozzles needed, and the amount of raw material used while still maintaining enough power for the system to be highly effective.

What Lechler USA Does with Computational Fluid Dynamics:

Now that we’ve defined CFD and briefly covered how the concept is used, let’s talk about why it matters to your spray system selection.  At Lechler US, there are three ways we use computational fluid dynamics to influence our spray system design:

  1. Flow field: We use computational fluid dynamics to calculate the flow field and pressure with one or multiple flowing fluids in a series of pipes and fittings.
  2. Spray propagation:  We use computational fluid dynamics to monitor and evaluate spray transmission, mass, heat and gas transfers under every conceivable condition.
  3. Nozzle placement: We use computational fluid dynamics to calculate and create nozzle placement and flow. With this, we make predictions of the spray pattern effectiveness and efficiency, how the water will be distributed, and the unique characterization of the droplet sizes and how and where they will fall.[4]

By combining the data above, the possibilities for creation and development at Lecher USA are endless.  Our services permit us to make customized nozzle structures and spray systems that are guaranteed to be effective for your business and needs.  We use the computational fluid dynamic process to create a sustainable and productive spray system for you.  Whatever your needs are, we are ready, experienced, and able to accommodate your specific priorities.

Nozzles and Spray Simulations

At Lechler USA, we have 140 years of experience creating exceptional spray system cleaning solutions.

Some examples of computational fluid dynamics in use are available in our Fluid Dynamics Brochure. Here, you will find a variety of unique nozzles, and how the computational fluid dynamics software created a colorful diagram to show the velocity of the water distribution and projections. 

The Laval Nozzle:

This simulation clearly demonstrates the effectiveness of this technology. “The Laval nozzle from Lechler is a twin-fluid nozzle with an internal mixing chamber that can be used in a large number of different applications. Normally, water is pre-atomized in the mixing chamber by means of compressed air. Significant post-atomization is then achieved further on in the nozzle.”[6]  

The diagram provided clearly shows the higher velocity of the fluid entering the first chamber. That fluid is in a turbulent mix until it is released into the lower chamber, at which point you can see the fluid disbursement change, lessen, and fall more systematically.

Washing Tower for the Treatment of Process Gases

“Flue gas desulphurization is one of the best known ‘gas washing’ processes. In addition, there are countless other washing principles such as denitrification or the cleaning of particle-loaded gas flows. However, all washers have one thing in common: By using spray nozzles, the gas treatment should work as efficiently as possible over the shortest path or in the smallest possible space, while at the same time providing sufficient flexibility for all load cases. The flow simulation assists in this case to determine three key factors: (1) Nozzle selection (2) Nozzle arrangement and (3) Operating point(s). Considering your requirements, we determine the optimal washer configuration for each process. A downstream droplet eliminator is mandatory in most washers. Again here, flow simulation can help with a custom design.”[7]

SCALEMASTERⓇ Descaling Nozzle:

Another simulation that is helpful to see how computational fluid dynamics create guidance and perspective is the SCALEMASTERⓇ descaling nozzle simulation. “The SCALEMASTERⓇ from Lechler is a high-pressure flat spray nozzle for descaling hot steel prior to rolling. The water passes through a filter and a steel funnel before it is finally delivered in an extremely targeted and non-atomized spray.”[8] The computational fluid dynamic software created diagram demonstrates the likeliness of this nozzle's efficiency.  This nozzle, unlike the Laval, creates a powerful and direct spray.

Holistic Optimization of Evaporative Coolers:

Perhaps one of the best examples of computational fluid dynamics in action is the graphic for Lechler USA’s Holistic optimization of evaporative coolers. “Due to increasing environmental requirements and changed loads, evaporative coolers are often operated far from the original design. This often results in inefficient operation, wet floors and walls, and/or massive caking that can affect the overall structural analysis. 

With flow simulation of the complete process allows optimization potential to be found and the right steps to be initiated. All physical effects are simulated here, from the inflow of the hot flue gas through spray injection including evaporative cooling up to outflow of the cold, moist flue gas. The main results obtained are the pressure loss of the overall cooler as well as the spray trajectories.”[9]

How does the Holistic optimization of evaporate coolers benefit the consumer? This process provides dry walls and floors for operational safety, reduces energy consumption, provides cost reduction as a result of more efficient use of consumables such as compressed air or high-pressure water.[10]

These four are just a handful of the dozens of unique nozzles provided by Lechler USA for individual use and purposes. Whatever your individual needs are, we are confident we can find or design the right spray system or nozzle for you. 

Do You Have More Questions about Computational Fluid Dynamics?

Lechler USA is a leader in nozzle fabrication, production, and fluid disbursement optimization. With nearly 150 years of experience taking on tough jobs with innovative technologies, “we do not promise perfection - we expect it.” We take a great deal of pride in our innovative technologies, research, staff, and development, and our use of computational fluid dynamics is no exception.

When it comes to selecting the best spray systems for your business and your applications, there is no better match than Lechler USA. Our expertise and lab-tested advancements in fluid flow, turbulence, and the other factors that go into creating highly complex spray systems, ensures you have the best answers to all your spray system questions.

For more information on computational fluid dynamics, contact us by phone at: (800) 777-2926, by fax at: (630) 377-6657, or by email at: info(at) Alternately, click here to upload a pitch or inquiry, and someone from our staff will reach out to you for further assistance.