Design Optimization of a Shell and Tube Heat Exchanger for a Helicopter Considering Objective Functions of Heat Exchanger Weight, Overall Heat Transfer Coefficient, and Manufacturing Cost

In the current study, the optimal design of a shell-and-tube heat exchanger based on the TEMA standard is performed to preheat JP-4 fuel using neopentyl polyol ester (PE-DPE-316) engine oil for the purpose of refurbishing and upgrading the Bell AH-1 Cobra helicopter. The design considers three objective functions: heat exchanger weight, overall heat transfer coefficient, and manufacturing cost. Weight reduction and performance enhancement have consistently been priorities for designers in aerospace systems. For the first time, the reduction of heat exchanger’s weight is considered in this research for weight reduction in a helicopter. Design parameters include heat exchanger type (front head, shell, and rear head) comprising five types of floating head shell and tube heat exchangers (AES, AET, BET, AEP, and BEP), four types of U-tube heat exchangers (AEU, BEU, CEU, and CFU), and three types of fixed tube sheet heat exchangers (AEL, BEM, and NEN). Additional parameters are baffle type (single-segment, double-segment, and triple-segment) and baffle cut (20 to 35 percent of shell diameter). The heat exchanger design is performed using ASPEN EDR software and validated through the analysis of shell-side (engine oil) and tube-side (fuel) heat transfer relationships, with coding implemented in MATLAB. A good agreement is seen between the ASPEN EDR software and the MATLAB code. The final heat exchanger design in this study is a BEM type, single-pass with 0.75-inch outer tube diameter and single-segment baffles with a 20% cut. This design achieves a heat exchanger weight of 192.4 kg, an overall heat transfer coefficient of 193.7 W/m²·K, and a manufacturing cost of $20,398.