This thesis presents the results of computational fluid dynamics (CFD) design calculations of a subsonic nozzle operating at Mach number 0.85 in a transonic linear cascade wind tunnel. The purpose of the nozzle is to accelerate a fluid by decreasing the pressure energy and raising the kinetic one. The challenge in a nozzle design is to obtain uniform flow at the desired velocity. This parameter is examined in this project measuring the total pressure loss, boundary layer thickness, and exit flow angle. These measures have been the drivers for the present nozzle design. A quasi-one-dimensional approach implemented in Python programming was performed for the first design phase of the project. Subsequently, a mesh independence study was done and five wall contours were tested using the software package from ANSYS (ICEM CFD & CFX). The purpose of the CFD simulations was to determine the nozzle's optimum geometry to achieve flow uniformity in the nozzle outlet. It was found that the 5th order polynomial wall contour proposed by NASA was the best one concerning flow uniformity. Afterwards, the drawings and CAD model of the selected nozzle was produced with Autodesk Inventor. Finally, a turbulence model comparison among SST and k—ε is presented. It was confirmed that k—ε can be used for saving computational resources without loosing significant accuracy in the CFD simulation results.
| Identifer | oai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kth-298845 |
| Date | January 2021 |
| Creators | Lucio, César |
| Publisher | KTH, Energiteknik |
| Source Sets | DiVA Archive at Upsalla University |
| Language | English |
| Detected Language | English |
| Type | Student thesis, info:eu-repo/semantics/bachelorThesis, text |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | TRITA-ITM-EX ; 2021:268 |
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