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ABSTRACT
In this study, numerical simulations are conducted to investigate the effects of bowed outlet guide vanes (OGVs) on endwall heat transfer and aerodynamic performance. Both on- and off-design conditions are studied. For bowed vanes, the bowed angle varies from 10° to 40° and the normalized bowed height ranges from 0.1 to 0.3. Results are included for Nusselt number distributions on the endwall, the energy losses, the yaw angles, and near-wall flow structures. For the convenience of comparison, the straight vane is also studied as a baseline. It is found that the bowed vanes can effectively reduce the endwall heat transfer. Among the tested parameters, a bowed angle of 40° and a normalized bowed height of 0.3 provide the best-controlled heat transfer for both the on- and off-design conditions. However, the bowed vanes have different effects on the energy losses and the yaw angles depending on the operating conditions. For the on-design condition with the inlet angle of 30° (the incidence angle is 0°) and the off-design condition with the inlet angle of 0°, the bowed vanes do not significantly increase the energy losses and yaw angles, whereas for the off-design condition with the inlet angle of −30°, significant changes are observed.
Nomenclature
| Cp | = | specific heat of air |
| h | = | heat transfer coefficient |
| Hhub | = | normalized hub bowed height |
| Htip | = | normalized tip bowed height |
| L | = | vane chord |
| Nu | = | Nusselt number |
| = | inlet total pressure | |
| p1 | = | outlet pressure |
| q | = | heat flux |
| Re | = | Reynolds number |
| S | = | span |
| T | = | temperature |
| = | total temperature of inlet air | |
| Tw | = | endwall temperature |
| Tair | = | inlet temperature of air |
| U0 | = | free stream velocity |
| w | = | outlet averaged velocity |
| X | = | stream-wise length |
| y | = | lateral (circumferential) direction |
| α | = | inlet angle |
| β | = | Yaw angle |
| γ | = | specific heat ratio |
| γhub | = | hub bowed angle |
| γtip | = | tip bowed angle |
| η | = | energy loss |
| λ | = | thermal conductivity of air |
| μ | = | dynamic viscosity |
| ρ | = | density |
| Abbreviations | = | |
| OGV | = | Outlet guide vane |
Nomenclature
| Cp | = | specific heat of air |
| h | = | heat transfer coefficient |
| Hhub | = | normalized hub bowed height |
| Htip | = | normalized tip bowed height |
| L | = | vane chord |
| Nu | = | Nusselt number |
| = | inlet total pressure | |
| p1 | = | outlet pressure |
| q | = | heat flux |
| Re | = | Reynolds number |
| S | = | span |
| T | = | temperature |
| = | total temperature of inlet air | |
| Tw | = | endwall temperature |
| Tair | = | inlet temperature of air |
| U0 | = | free stream velocity |
| w | = | outlet averaged velocity |
| X | = | stream-wise length |
| y | = | lateral (circumferential) direction |
| α | = | inlet angle |
| β | = | Yaw angle |
| γ | = | specific heat ratio |
| γhub | = | hub bowed angle |
| γtip | = | tip bowed angle |
| η | = | energy loss |
| λ | = | thermal conductivity of air |
| μ | = | dynamic viscosity |
| ρ | = | density |
| Abbreviations | = | |
| OGV | = | Outlet guide vane |