By Michael Engelman, Enductive Solutions, a sister company of Fluent

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Instrumented cooking tray, showing thermocouples at the surface of the peas and water left in the tray after the cooking was completed

Despite the fact that computer aided engineering (CAE) use is widening across dozens of industries, the investment in personnel, hardware, and/or software is beyond the reach of many companies. Even if a focused, turn-key product were available, the know-how to develop such a product often is not. At Enductive Solutions, CAE solutions are created for a specific application, through the use of one or more software products that are integrated into a single, easy-to-use package.

In one recent project, a manufacturer of commercial food steamers wanted to increase the capacity and efficacy of a steamer for a customer's special requirements. The first step was to investigate the functionality of the existing device. It was determined that CFD would be needed, so Enductive engineers worked with the manufacturer on physical testing to develop boundary conditions and a set of data that would later be used for validation studies. The steamer was instrumented with appropriate velocity probes and thermocouples and tested under four different operating conditions. The tests showed that uneven heat distribution within the steamer would make it impossible to improve its performance without significant design changes.

Experimental profiles of temperature vs. time as measured by the thermocouples positioned in the tray

Enductive engineers then obtained a copy of the computer aided design (CAD) file for the steamer and used it to create the geometry and mesh for a CFD simulation. Boundary conditions and physical properties were derived from the test results and information provided by the manufacturer. The results of the CFD simulation helped to explain the uneven temperature distributions shown in the physical tests. In particular, they showed that the location, speed, and direction of the steam jets were far more important than the gas flow rate entering the unit or distribution of food inside the unit in governing the temperature distribution in the steamer.

The results suggested that the operation of the steamer could be greatly improved by any change that results in a more uniform flow distribution, such as relocation of the jets, or introduction of manifolds, steam exhaust valves, or recirculating fans. They also made it clear that future CFD simulations of the steamer could be done without heat transfer calculations, since the flow pattern alone determines the temperature distribution throughout the device.

The next step was to encapsulate the CFD analysis within an interface that prompts the user to enter only a few critical design parameters, such as the vessel size, tray locations, and steamer type. The tool then performs the appropriate CFD calculation and returns the results necessary to evaluate the performance of the design.

Steam pathlines, colored by velocity magnitude, illustrate the improved flow field in the steamer
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Application-specific solutions such as this can be done on-site or can be deployed to a CAE specific Applications Service Provider (ASP) such as the Fluent Remote Simulation Facility. The customer can enter the parameters needed to perform the analysis in a matter of minutes and does not need to spend the time that would otherwise be required to become an analysis expert. The use of an ASP to perform the analysis eliminates the need to purchase and maintain expensive software and hardware as well. The analysis returns the precise information that the user needs to determine the performance of the proposed design and, just as importantly, helps provide an understanding of why the design does or does not work so that it can quickly be improved. The service puts advanced CAE tools in the hands of the people who need them most - front line engineers - to reduce engineering expenses and bring products to market faster.

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