Example Problem Fluid Statics

In general, fluids exert both normal and shearing forces. This section reviews a class of problems in which the fluid is at rest. A velocity gradient is necessary for the development of a shearing force, so in the case where acceleration is equal to zero, only normal forces occur. These normal forces are also known as hydrostatic forces. In Fig. 1.16 a point in a fluid P1 is shown at a depth of h below the surface of the fluid. The pressure exerted at a point in the fluid by the column of fluid...

Pulsatile Flow in Large Arteries

Let us begin with the mathematical description of the motion of the fluid elements moving in a flow field. It will be convenient to express the velocity in terms of three Cartesian components so that velocity becomes a function of x, y, and z spatial coordinates, as well as a function of time. Also u, v, and w are the velocity components in the x, y, and z directions, respectively. Written in a concise form V ui + vj 1 wk u(x,y,z,t)i + v(x,y,z,t)j + w(x,y,z,t)k The corresponding expressions for...

Mechanics of Heart Valves

Four cardiac valves help to direct flow through the heart. Heart valves cause blood to flow only in the desired direction. If a heart without heart valves were to contract, it would simply squeeze the blood causing it to flow both backward and forward (upstream and downstream). Instead, under normal physiological conditions, heart valves act as check valves to prevent blood from flowing in the reverse direction. Also, heart valves remain closed until the pressure behind the valve is large...

Anatomy and Physiology of Blood Vessels

Arteries are the high-pressure blood vessels that transport blood from the heart through increasingly smaller arteries, to arterioles and further to the level of capillaries. Veins conduct the blood from the capillaries back to the heart on the lower pressure side of the cardiovascular system. The structure of arteries and veins as well as their mechanical properties are discussed in this chapter. At any given time, about 13 percent of the total blood volume resides in the arteries and about 7...