Effect of Streamlined Nose Length on the Aerodynamic Performance of a 800 km/h Evacuated Tube Train

Theoretical and numerical studies on compressible flow around a subsonic evacuated tube train

“…NICK et al 13 studied the aerodynamic flow separation position of the evacuated tube aircraft, using numerical simulation, and the aerodynamic shape of the aircraft was optimized. ZHANG et al 14 studied the effect of the streamline length of an evacuated tube train on its aerodynamic resistance, using computational fluid dynamics. ZHANG et al 15 explained the phenomenon of the aerodynamic choked state in the front of the train by the theory of air intake, and studied the aerodynamic choked characteristics inside the tube, by means of the overset mesh technique.…”

Design and Optimisation of a Virtual Prototype of a Ground Transportation System at Very High-Speeds in Conditions Close to Vacuum

“…A similar study was performed by Zhang [82], who varied the nose length to reduce the aerodynamic drag more than a 2 % at 0.2 atm 1 and 800 km/h, with a BR equal to 0.2. Oh et al [87] analysed a wide range of pressures, concluding that the pressure drag was significantly affected by the increase in the BR.…”

“…This corresponds to 140 times the height h of the capsule, which is considered enough for this case. Other authors used smaller domains, such as Zhang et al [82] who used 27h upstream and 50h downstream, Oh et al [87] who used 1.76L upstream and 5.65L downstream, Bao et al [92] who used 31.25h and 69h, and Li et al [86] who used 34h and 78h respectively. Another input parameter is required to define the tunnel height.…”

“…Regarding the thermodynamic parameters, the specific heat ratio γ and ideal gas constant for the air R, are considered invariant with the pressure. Regarding the viscosity, the Sutherland model has been used as in [87,82,85].…”

“…Kwon et al [80] used the response surface methodology and axisymmetric compressible Euler equations to optimise the nose shape of a train and minimise the tunnel compression wave. More work about nose optimisation was conducted by Choi and Kim in [81] and by Zhang in [82].…”