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The relationship between atomizing gas molecular weight and spray mean drop size, Rosin-Rammler distribution parameter, and number averaged drop velocity is reported for a low mass flowrate effervescent atomizer-produced spray. Experimental data at lower gas-liquid ratios (GLR’s) demonstrate that an increase in the molecular weight of the atomizing gas increases mean drop size and decreases number averaged drop velocity. The increase in mean drop size is attributed to an increase in the thickness of the liquid annulus at the nozzle exit and a subsequent increase in the diameter of ligaments formed there. The decrease in number averaged velocity results from a decrease in jet momentum rate. A model developed to explain the atomization process indicates that the gas flow is choked at higher GLR’s.

The implementation of a virtual engineering system at John Zink Company, LLC is starting to change the engineering and development processes for industrial combustion equipment. This system is based on the virtual engineering software called VE-Suite being developed at the Virtual Reality Applications Center (VRAC) of Iowa State University. The goal of the John Zink virtual engineering system is to provide a virtual platform where product design, system engineering, computer simulation, and pilot plant test converge in a virtual space to allow engineers to make sound engineering decisions. Using the virtual engineering system, design engineers are able to inspect the layout of individual components and the system integration through an immersive stereo 3D visualization interface. This visualization tool allows the engineer not only to review the integration of subsystems, but also to review the entire plant layout and to identify areas where the design can be improved. One added benefit is to significantly speed up the design review process and improve the turn around time and efficiency of the review process. Computational Fluid Dynamics (CFD) is used extensively at John Zink to evaluate, improve, and optimize various combustion equipment designs and new product development. Historically, design and product development engineers relied on CFD experts to interpret simulation results. With the implementation of the virtual engineering system, engineers at John Zink are able to assess the performance of their designs using the CFD simulation results from a first person perspective. The virtual engineering environment provided in VE-Suite greatly enhances the value of CFD simulation and allows engineers to gain much needed process insights in order to make sound engineering decisions in the product design, engineering, and development processes. Engineers at John Zink are now focusing on taking the virtual engineering system to the next level: to allow for real-time changes in product design coupled with high-speed computer simulation along with test data to optimize product designs and engineering. It is envisioned that, when fully implemented, the virtual engineering system will be integrated into the overall engineering process at John Zink to deliver products of the highest quality to its customers and significantly shorten the development cycle time for a new generation of highly efficient and environmentally friendly combustion products.

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