TEG Design for Waste Heat Recovery at an Aviation Jet Engine Nozzle

Abstract

Finite element model (FEM)-based simulations are conducted for the application of a thermoelectric generator (TEG) between the hot core stream and the cool bypass flow at the nozzle of an aviation turbofan engine. This work reports the resulting requirements on the TEG design with respect to applied thermoelectric (TE) element lengths and filling factors (F) of the TE modules in order to achieve a positive effect on the specific fuel consumption. Assuming a virtual optimized TE material and varying the convective heat transfer coefficients (HTC) between the nozzle surfaces and the gas flows, this work reports the achievable power output. System-level requirement on the gravimetric power density (>100 Wkg −1 ) can only be met for F ≤ 21%. When extrapolating TEG coverage to the full nozzle surface, the power output reaches 1.65 kW per engine. The assessment of further potential for power generation is demonstrated by a parametric study on F, convective HTC, and materials performance. This study confirms a feasible design range for TEG installation on the aircraft nozzle with a positive impact on the fuel consumption. This application translates into a reduction of operational costs, allowing for an economically efficient TEG-installation with respect to the cost-specific power output of modern thermoelectric materials.

Aircraft thermal management: Practices, technology, system architectures, future challenges, and opportunities

“…However, the efficiencies of these materials are improving, and different types of installation architectures may improve the power density to such an extent that they become more attractive for larger scale use. Indeed, Ziolkowski et al [171] has shown that when placing thermoelectric generators between the hot core stream and cold bypass flow of a gas turbine engine, a feasible design range can be obtained, with a beneficial effect on aircraft specific fuel consumption. The TRL for the implementation of thermoelectric heat sinks in aircraft has been placed at between 3 and 4 [102].…”

Potential of Recycled Silicon and Silicon-Based Thermoelectrics for Power Generation

“…Other alternative locations worth exploring include the aircraft engine and nozzle, where a large amount of heat is expended throughout the course of the flight [109]. However, as the geometry at these areas is slightly more complicated than that of a flat surface, more considerations are included in designing the device.…”

“…For commercial planes, there are multiple possible locations to install thermoelectric devices-the most common being the fuselage, where low-temperature thermoelectrics are utilized for powering WSNs [153,154]. Looking toward further usage of thermoelectrics in commercial aviation, models have been constructed around the installation of thermoelectric generators at the plane engine nozzles [109]. As previously mentioned, the temperature gradient in this area can be large.…”

Energy Harvesting Technologies for Structural Health Monitoring of Airplane Components—A Review

“…1.65 kW per engine. With higher nozzle surface coverage and improved heat sink design, the obtained power output could be increased to even 3 kW [153]. An approach where exhaust gases were used to increase the temperature of the hot side of the TEG module was recently experimentally investigated on a jet engine as well [154].…”