Some comments on turbulence modeling from an industrial perspective

In propulsion industry, computational techniques (namely computational fluid dynamics) are gradually becoming engineering design and analysis tools, especially in the case of high performance aircraft engines, high speed air breathing propulsion, rocket propulsion, and advanced nuclear propulsion and electric propulsion. The key issues in acceptance of CFD are turn around time, cost, and accuracy. The turn around time of analysis has to fit program schedules. Cost is still the bottom line, the value of CFD to the program should at least balance its cost. CFD can be used if it can be divided into two major parts: numerics and physical models.