This Manual may not be sold and may not be distributed to or used by any student or other third party. Mecanica De Fluidos Cengel Cimbala Pdf To Word Online.This Manual is being provided only to authorized professors and instructors for use in preparing for the classes using the affiliated textbook. Mecanica-de-fluidos-fundamentos-y-aplicaciones-yunus-cengel-y-john-cimbala-primera-edicionThe mass or region outside the system is called the surroundings. The development of a boundary layer is caused by the no-slip condition.If you are a student using this Manual, you are using it without permission. The region of flow in which the velocity gradients are significant and frictional effects are important is called the boundary layer. No part of this Manual may be reproduced, displayed or distributed in any form or by any means, electronic or otherwise, without the prior written permission of McGraw-Hill. Discussion It turns out that the Mach number is the critical parameter to determine whether the flow of a gas can be approximated as an incompressible flow.A flow fluldos which density varies significantly is called compressible flow.