Monthly Archives: April 2015

Thermal Analysis using Computational Fluid Dynamics (CFD)

Complex engineering solutions are, well, ‘complex’.  That accurately describes the challenge of recent job for a global metal manufacturing firm.  In this job Sigma was to reverse engineer and model a heat exchanger that is used in a foundry for creating alloy steel bars. In this application, hot metal flows in from one side, at 2800 °F, and is cooled by water that enters in from the other side. When the metal exits, it will be solidified to 1700 °F. The water and metal never touch, and because of the high heat, the heat exchanger itself had some very complex geometry and materials. Sigma was tasked with this project because of their engineering and design experience. The client’s heat exchanger had very poor engineering documentation (no drawings or specifications), and was largely untouched for many years. As a result, the orientation of a few components was unknown, and it became critical to understand which way the heat exchanger should be assembled.

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A SolidWorks Simulation CFD was run to determine the fluid flow profile. By running the simulation with different configurations of the heat exchanger, we could see which configuration provided better flow and therefore better system temperature control. We created areas where the flow rate could be measured, and used that data to determine the proper orientation of the components. Basically, the larger the flow rate near the hottest point in the assembly the better, because that will lead to greater convection, and essentially better heat removal.  Problem solved!

Hydraulic Power Test System Development for the United States Navy

Ken DeGraw, Sigma Design Company’s northern NJ rep recently brought in a very interesting project. We are working on a NAVSEA research program to design and build a large Hydraulic Power supply for the US Navy’s weapon testing system.CIMG3348

Sigma is very excited to work on a project with the US Navy. Talk about a project in ‘our wheelhouse’ as they say. Jerry Lynch, a ‘tin can sailor’ who served as a destroyer GMG2 gunner was thrilled to have the opportunity to work on this special project supporting shipboard defense systems for Navy operations.
Michael Collins, the lead engineer on the NAVSEA project worked for the US Navy in Philadelphia before coming to Sigma. This project requires the creative design of safety features while providing 50% more power through their
Hydraulic Power Supply system. With operating pressures in excess of 3000psi the pressure compensation and hydraulic shock suppression systems were key features in the new design. This system joins the growing roster of Sigma’s manufactured in NJ products- designed and built in NJ. Sigma is proud to have the opportunity to work with the Navy to improve operational shipboard defense systems used around the globe but made in NJ.