Infrared Thermography Investigation of Heat Transfer on Outlet Guide Vanes in a Turbine Rear Structure

Abstract

Aerothermal heat transfer measurements in fluid dynamics have a relatively high acceptance of uncertainty due to the intricate nature of the experiments. The large velocity and pressure gradients present in turbomachinery application add further complexity to the measurement procedure. Recent method and manufacturing development has addressed some of the primary sources of uncertainty in these heat transfer measurements. However, new methods have so far not been applied in a holistic approach for heat transfer studies. This gap is bridged in the present study where a cost-effective and highly accurate method for heat transfer measurements is implemented, utilising infrared thermography technique (IRT) for surface temperature measurement. Novel heat transfer results are obtained for the turbine rear sturcture (TRS), at engine representative conditions for three different outlet guide vane (OGV) blade loading and at Reynolds Number of 235000. In addition to that, an extensive description of the implementation and error mitigation is presented.

Detailed Experimental Study of the Flow in a Turbine Rear Structure at Engine-Realistic Flow Conditions

“…Thorough aerodynamic studies as well as numerical investigation of the TRS with regular vanes are presented in Refs. [8,9,12].…”

“…This work highlighted the effect of the turbine tip clearan ce on the losses and the importance of an engine realistic LPT stage. Further investigations in a newly established TRS facility at Chalmers University of Technology [7][8][9] were carried out in a rig equipped with a realistic shrouded LPT and operated at engine-realistic flow Reynolds numbers. The design of the new rig is presented by Rojo et al [7].…”

“…The design of the new rig is presented by Rojo et al [7]. Jonsson et al [8] presented the accurate measurements of the heat transfer coefficient on OGVs, which has allowed for the mapping of the laminar-turbulent transition on OGVs for a number of aerodynamic load cases and his work is further extended and compared to CFD in an accompanying paper [10]. Jonsson et al [9] illustrated the impact of surface roughness on secondary flows and pressure losses in a TRS.…”

“…Jonsson et al [9] illustrated the impact of surface roughness on secondary flows and pressure losses in a TRS. Both studies [8,9] highlighted the significance of the laminar-turbulent transition on the performance of the TRS.…”

“…The studies [7][8][9] were performed for TRS consisting of 12 so-called regular vanes, however a typical modern TRS design includes several (2 or more) vanes equipped with an engine mount recess (also called a shroud bump) and several (typically 2-3) thickened vanes. The role of the engine mount recess is to structurally enforce the TRS at the attachment points of the engine to the aircraft.…”