Experimental and Computational Investigation of Flow Structure in Buoyancy-Dominated Rotating Cavities

Abstract

The flow and heat transfer inside HP compressor rotating cavities are buoyancy driven and are known to be extremely difficult to predict. The experimental data of Laser-Doppler Anemometry (LDA) measurements inside an engine representative cavity rig is presented in this paper. Traverses using a two component LDA system have been carried out in the shaft bore and the cavity regions in order to map the axial and tangential velocity components. The velocity data is collected for a range of Rossby, Rotational and Axial Reynolds numbers, Ro, Re? and Rez : 0.08<Ro<0.64,7×?10?^5<?Re?_?<2.83×?10?^6,1.2×?10?^4<?Re?_z<4.8×?10?^4 and for values of the buoyancy parameter ß??, 0.284< ß?T<0.55. Numerical study using unsteady Reynolds Averaged Navier-Stokes (URANS) simulations have been carried out to elucidate flow details for a few selected cases. The experimental results revealed that the Swirl number (Xk) varies from a value < 1 near the bore to near solid body rotation at increased radii within the cavity. The analysis of frequency spectrum of the tangential velocity inside the cavities has also shown the existence of pairs of rotating and contra-rotating vortices. There is generally satisfactory agreement between measurements and CFD simulations. There is also convincing evidence of two or more separate regions in the flow dominated by the bore flow and rotation.

A Model of Mass and Heat Transfer for Disc Temperature Prediction in Open Compressor Cavities

“…The data indicated the structure in the high-radius region of the cavity dominated by buoyancy-induced flow had a proportional dependency on Re 𝜙 , but was insensitive to Re 𝑧 . Fazeli et al [6] used LDA measurements to study the flow structure and compared the results with Unsteady Reynolds-Average Navier-Stokes (URANS) calculations. They showed the cavity was separated into two regions: one dominated by bore flow and the other by buoyancy.…”

Experimental and computational investigation of flow structure of buoyancy induced flow in heated rotating cavities

“…The distribution of the thermocouples in the cavity was shown earlier in Figure 3. A comprehensive discussion of the experimental apparatus and measuring technique is provided by Fazeli et al (2020).…”

Heat transfer enhancement of magnetized nanofluid flow due to a stretchable rotating disk with variable thermophysical properties effects

“…The viscosity of magnetic fluids and flow characteristics play a significant part in the optimization of ferrofluid properties and as such, various computational techniques have been employed to tackle the difficulty of heat transport characteristics and nanofluids in the existence of strong magnetic field and varying thermal conductivity in various rotating channels such as deformable rotating disk, [35,36], rotating cavities [37,38], porous disk [39,40], rotating cavity with radial outflow [41,42], dual rotating extendable disk [43,44]. Viscosity and thermal conductivity are very sensitive to temperature rise, which usually results in significant changes in the physical properties of the fluid, most especially in the theory of lubrication, where they are being affected by the heat produced through the internal friction and a corresponding temperature rise.…”