PROLOGUE

This chapter deals with the enhancement of rates of mass, momentum, and heat transfer. This is desired to improve the performance of mixers of nonreacting species; chemical reactors, including combustors; lifting surfaces; heat exchangers, including those in HVAC systems; and numerous other man-made devices. In nature, the efficient turbulence mixing is responsible for the nearly uniform distribution of oxygen, carbon dioxide, and internal energy in the Earth's atmosphere and oceans. Without that more-or-less uniform distribution, seasonal and latitudinal temperature changes would be even more extreme. Oxygen would be more concentrated in the equatorial rain forests, and carbon dioxide would be more concentrated in industrial and urban centers. Under such circumstances, city dwellers at least would not survive long on this third planet from the sun. In plants and animals, the efficient transport of mass and energy through limited spaces is also vital for their survival. The subject of mixing enhancement is very broad, is important to entire industries, and is covered extensively in many journals and books.