TY - JOUR
T1 - Study of a high-reliability dual-fan system for cooling aerospace electromechanical actuators
AU - Mesalhy, Osama
AU - Elsayed, Mohamed L.
AU - Corona, Jose J.
AU - Kwarteng, Augustine A.
AU - Kizito, John P
AU - Leland, Quinn H.
AU - Chow, Louis C.
PY - 2020/8/1
Y1 - 2020/8/1
N2 - There is an increasing trend for incorporating Electro-Mechanical Actuators (EMAs) in aerospace applications to reduce weight and cost. Due to the high-power density required for EMAs in aircraft applications, they are prone to overheating. Pushing the wing-bay air on a finned EMA surface using axial flow fans is the most practical way to cool the EMAs used for flight control surfaces. The probability of failure of the commercial fans is 2 × 10−5 which is too high compared to the desired failure probability of 10−9 for the EMAs. This paper presents a validated numerical simulation to assess the performance of dual fans in cooling EMAs. The two fans are set in a series arrangement due to the space limitation in the wing bay. Only one fan is allowed to rotate, while the second backup fan is clamped to eliminate wear in its bearing. In case of failure of the running fan, the other fan will be switched on immediately. The results show that the performance of the dual fan is much better when the upstream fan is running. Due to flow blockage by the stationary upstream fan, the performance of the operating downstream fan decreases significantly. Different options have been explored to improve the performance in the case of running the downstream fan, such as removing the diffuser section, changing the distance between the two fans and opening the circumferential duct wall between the two fans. It is found that operating the downstream fan with open wall results in comparable performance as operating the upstream fan with closed wall. This means that using a movable wall to facilitate the opening and closure of the circumferential duct wall between the two fans can improve the reliability and effectiveness of the cooling system with two fans, with one serving as the backup. With this redundancy, the failure probability of the cooling system drops from 2 × 10−5 to 4 × 10−10.
AB - There is an increasing trend for incorporating Electro-Mechanical Actuators (EMAs) in aerospace applications to reduce weight and cost. Due to the high-power density required for EMAs in aircraft applications, they are prone to overheating. Pushing the wing-bay air on a finned EMA surface using axial flow fans is the most practical way to cool the EMAs used for flight control surfaces. The probability of failure of the commercial fans is 2 × 10−5 which is too high compared to the desired failure probability of 10−9 for the EMAs. This paper presents a validated numerical simulation to assess the performance of dual fans in cooling EMAs. The two fans are set in a series arrangement due to the space limitation in the wing bay. Only one fan is allowed to rotate, while the second backup fan is clamped to eliminate wear in its bearing. In case of failure of the running fan, the other fan will be switched on immediately. The results show that the performance of the dual fan is much better when the upstream fan is running. Due to flow blockage by the stationary upstream fan, the performance of the operating downstream fan decreases significantly. Different options have been explored to improve the performance in the case of running the downstream fan, such as removing the diffuser section, changing the distance between the two fans and opening the circumferential duct wall between the two fans. It is found that operating the downstream fan with open wall results in comparable performance as operating the upstream fan with closed wall. This means that using a movable wall to facilitate the opening and closure of the circumferential duct wall between the two fans can improve the reliability and effectiveness of the cooling system with two fans, with one serving as the backup. With this redundancy, the failure probability of the cooling system drops from 2 × 10−5 to 4 × 10−10.
KW - Aerospace
KW - Air cooling
KW - Dual-fan
KW - Electro mechanical actuator
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U2 - 10.1016/j.tsep.2020.100540
DO - 10.1016/j.tsep.2020.100540
M3 - Article
SN - 2451-9049
VL - 18
JO - Thermal Science and Engineering Progress
JF - Thermal Science and Engineering Progress
M1 - 100540
ER -