Velocity Triangle as long as Turbo-machinery BY P M V Subbarao Professor Mechanical Eng

Velocity Triangle as long as Turbo-machinery BY P M V Subbarao Professor Mechanical Eng www.phwiki.com

Velocity Triangle as long as Turbo-machinery BY P M V Subbarao Professor Mechanical Eng

Dragin, Burt, Faculty Advisor has reference to this Academic Journal, PHwiki organized this Journal Velocity Triangle as long as Turbo-machinery BY P M V Subbarao Professor Mechanical Engineering Department I I T Delhi U Vri Vre

San Joaquin Valley College-Online CA www.phwiki.com

This Particular University is Related to this Particular Journal

Vai: Inlet Absolute Velocity Vri: Inlet Relative Velocity Vre: Exit Relative Velocity Vae:Exit Absolute Velocity ai: Inlet Nozzle Angle. bi: Inlet Blade Angle. be: Exit Blade Angle. ai: Exit Nozzle Angle. Va Vr Vrc Vw U Vf Flow through Blades

Fluid Dynamics of Blades The stream is delivered to the wheel at an angle ai in addition to velocity Vai. The selection of angle ai is a compromise. An increase in ai, reduces the value of useful component (Absolute circumferential Component). This is also called Inlet Whirl Velocity, Vwi = Vai cos(ai). An increase in ai, increases the value of axial component, also called as flow component. This is responsible as long as definite mass flow rate between to successive blade. Flow component Vfi = Vai sin(ai) = Vri sin(bi). The absolute inlet velocity can be considered as a resultant of blade velocity in addition to inlet relative velocity. The two points of interest are those at the inlet in addition to exit of the blade. If the stream is to enter in addition to leave the blades without shock or much losses, then relative velocity should be tangential to the blade inlet tip. Vri should enter at an angle bi, the inlet blade angle. Similarly, Vre should leave at be, the exit blade angle. A blade is said to be symmetric if bi = be. The flow velocities between two successive blade at inlet in addition to exit are Vfi & Vfe. The axial (basic useful) components or whirl velocities at inlet in addition to exit are Vwi & Vwe.

Impulse Turbine Newton’s Second Law as long as an Impulse Blade: The tangential as long as ce acting of the jet is: F = mass flow rate X Change of velocity in the tangential direction Tangential relative velocity at blade Inlet : Vri cos(bi). Tangential relative velocity at blade exit : -Vre cos(be). Change in velocity in tangential direction: -Vre cos(be) – Vri cos(bi). -(Vre cos(be) + Vri cos(bi)). Tanential Force, The reaction to this as long as ce provides the driving thrust on the wheel. The driving as long as ce on wheel Power Output of the blade, Diagram Efficiency or Blade efficiency:

Define Blade Speed Ratio, f For a given shape of the blade, the efficiency is a strong function of f. For maximum efficiency:

Impulse-Reaction turbine This utilizes the principle of impulse in addition to reaction. There are a number of rows of moving blades attached to the rotor in addition to equal number of fixed blades attached to the casing. The fixed blades are set in a reversed manner compared to the moving blades, in addition to act as nozzles. The fixed blade channels are of nozzle shape in addition to there is a comparatively small drop in pressure accompanied by an increase in velocity. The fluid then passes over the moving blades in addition to , as in the pure impulse turbine, a as long as ce is exerted on the blades by the fluid. There is further drop in pressure as the fluid passes through the moving blades, since moving blade channels are also of nozzle shape. The relative velocity increases in the moving blades. p va vr The reaction effect is an addition to impulse effect. The degree of reaction

First law as long as fixed blades: 0 1 2 First law as long as moving blades: If the stream is to enter in addition to leave the blades without shock or much losses, then relative velocity should be tangential to the blade inlet tip. Vr1 should enter at an angle b1, the inlet blade angle. Similarly, Vr2 should leave at b2, the exit blade angle. In an impulse reaction blade, Vr2 > Vr1. The flow velocities between two successive blade at inlet in addition to exit are Vf1 & Vf2. The axial (basic useful) components or whirl velocities at inlet in addition to exit are Vw1 & Vw2. Newton’s Second Law as long as an Impulse-reaction Blade: The tangential as long as ce acting of the jet is: F = mass flow rate X Change of velocity in the tangential direction Tangential relative velocity at blade Inlet : Vr1 cos(b2). Tangential relative velocity at blade exit : -Vr2 cos(b2). Change in velocity in tangential direction: -Vr2 cos(b2) – Vr1 cos(b1). -(Vr2 cos(b2) + Vr1 cos(b1)). Tangential Force,

The reaction to this as long as ce provides the driving thrust on the wheel. The driving as long as ce on wheel Power Output of the blade, Diagram Efficiency or Blade efficiency: First law as long as fixed blades: First law as long as moving blades:

Dragin, Burt Laney Tower Faculty Advisor www.phwiki.com

Losses in nozzle, Nozzle blade loss factor, f For a given shape of the blade, the efficiency is a strong function of U/Va1. For maximum efficiency:

Dragin, Burt Faculty Advisor

Dragin, Burt is from United States and they belong to Laney Tower and they are from  Oakland, United States got related to this Particular Journal. and Dragin, Burt deal with the subjects like Higher Education; Local News; Student/Alumni Interest

Journal Ratings by San Joaquin Valley College-Online

This Particular Journal got reviewed and rated by San Joaquin Valley College-Online and short form of this particular Institution is CA and gave this Journal an Excellent Rating.