SpinOffs

When starting a turbomachinery design, the first choice an engineer has to make is the thermodynamic model. The actual fluid type (air, water, R1234ze, etc) is usually clear enough, but what model approach should be selected? Looking at the fluid dialog in Concepts NREC software shows a myriad of options to choose from.

On occasion I’m invited to a local middle school to give a talk to one of the science classes about ‘What Is Turbomachinery, and How Does It Work?’.   I teach in several of the turbomachinery design courses we give at Concepts NREC, and while I’m comfortable in those courses, presenting at this level was different. I originally found it a challenge to come up with a good presentation that would keep the students' attention, while still providing some science education as requested by the science teacher that invited me. Derivation of the Euler turbomachinery equation was probably out. The attention getters that seemed to work best to get the conversation going included bringing our turbocharger cut-away (definitely the biggest hit of anything I brought), along with other interesting impeller samples. From there getting into the purpose of various types of turbomachinery (compressor vs turbine vs pump) and a very high level discussion of energy transfer to/from a fluid, seemed to flow. Getting them thinking about some of the physical aspects of turbomachinery operation (Just how fast is 100,000 rpm?) also seemed to keep their attention.

Whether it’s a compressor, turbine, or an entire rocket turbopump design project we are tackling at Concepts NREC, we typically divide the design project into three phases: (1) scoping or feasibility study, (2) preliminary design, and (3) detailed design.   Each of these phases has a specific purpose, although where one phase ends and the next phase begins can vary from project to project.   The purpose and need for a scoping study was described in my blog posted last month, Why are Scoping Studies Necessary for Your Turbomachinery Project? In this blog I will describe the difference between preliminary design and detailed design.