2D Flow Field Analysis by the Exergetic Method

Velocity Decomposition Method for Exergy-Based Drag Prediction

“…26). This confirms the fact that the isentropic exergy field is not interesting for design purposes in 2-D cases [15] because the related exergy is self-recovered downstream since the flow particles follow an isentropic trajectory; they return to the original (equilibrium) state by following a reversible path. This highlights the need of decomposing the exergy formulations in order to retain only the interesting part of the exergy from a design point of view: the nonisentropic field.…”

“…This demonstrates that the decomposed exergy formulation is suited for wind-tunnel data analysis, whereas the original Arntz method requires an infinite survey plane integral since it also integrates the isentropic components (whose field varies at any point of the domain). Moreover, the C D ε distribution along the survey line matches the distribution of C D ε (not shown here for simplicity); thus, it will also differ from the Meheut profile drag distribution [15].…”

“…The interest of decomposing each term of the exergy equation into its isentropic and nonisentropic parst is related to the fact that the isentropic exergy is not useful from an engineering point of view for 2-D cases because it represents a self-recovered exergy [15]: the perturbed flow outside the wake will follow an isentropic process Fig. 3 Real velocity vector components.…”

“…Another powerful and promising method is the exergy analysis. This technique has been used during the last 20 years for external aerodynamic analysis, mostly in CFD and analytical applications [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. Particularly, the formulation proposed by Arntz [13] represents a major milestone in the development of the exergy method.…”

“…To reduce the exergy calculations to the wake region only, a major reformulation must be made. Very few works attempting to calculate the exergy parameters by only measuring the wake parameters have been published [15][16][17][18][19][20][21]. Nevertheless, it still lacks a formulation directly related to the Arntz method and capable of providing all the exergy and anergy components inside the wake.…”