1
FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
Compressors: A flow compressor is a mechanical
device that increases the pressure of a gas by
reducing its volume through dynamic or positive
displacement means.
Applications: Aerospace propulsion, gas turbines,
HVAC systems, industrial processing.
Classification of Compressors:
• Based on Flow Direction:
 Axial Flow Compressor
 Centrifugal (Radial) Flow Compressor
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
• Based on Staging:
• Single Stage Compressor
• Multistage Compressor
Single Stage Axial Compressor
• A compressor with one rotor and one stator stage.
Working Principle:
 Rotor imparts kinetic energy to the fluid.
 Stator converts kinetic energy to pressure energy.
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
Equations – Single Stage Compressor:
Euler’s Turbomachinery Equation: Δ h0 = U⋅ΔVθ
• Δh0​
: Stagnation enthalpy rise (J/kg)
• U: Blade speed at rotor tip (m/s)
• ΔVθ ​
: Change in tangential velocity component (m/s)
Isentropic Efficiency (ηs ) = [h02−h01] / [h02s−h01]
• ηis​
: Isentropic efficiency
• h02​
, h01​
: Total enthalpy at outlet and inlet
• h02s​
: Total enthalpy for isentropic process
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
6.Multistage Compressors
Consists of multiple rotor-stator stages to achieve
higher pressure ratios.
Advantages:
• Higher total pressure rise
• Improved efficiency with interstage cooling
Use Cases: Jet engines, industrial gas compressors
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
Multistage Compressor Performance
1.Total Pressure Ratio =
• ​
P0: Stagnation pressure
• T0​
: Stagnation temperature
• γ : Ratio of specific heats
2. Overall Efficiency ηoverall =
(T0,exit−T0,inlet) / (Ts
0,exit​
−T0,inlet​
​)
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
8: Velocity Triangles: Illustrates relative and
absolute velocities at blade inlet / outlet. The
figure 2, Show the Inlet and outlet velocity
triangles
Where
• V: Absolute velocity,
• U: Blade speed,
• W: Relative velocity
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
Degree of Reaction (R) = Δh rotor / Δh stage
= 1/2(1−V2θ+V1θ) / U
• Indicates the distribution of static enthalpy rise
between rotor and stator.
• Ideal for R=0.5, represents equal pressure rise
in rotor and stator.
Design Parameters:
• Tip Mach Number (Mt),
• Flow Coefficient ( )
ϕ = Vax / U
• Work Coefficient (ψ) =Δh0 / U2
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FLOW COMPRESSORS - SINGLE STAGE, MULTISTAGE
COMPRESSOR
Losses in Compressors
• Profile losses
• Secondary flow losses
• Tip clearance losses
• Skin friction
9

9 flow compressors-single stage, multistage compressor,.pptx

  • 1.
    1 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR Compressors: A flow compressor is a mechanical device that increases the pressure of a gas by reducing its volume through dynamic or positive displacement means. Applications: Aerospace propulsion, gas turbines, HVAC systems, industrial processing. Classification of Compressors: • Based on Flow Direction:  Axial Flow Compressor  Centrifugal (Radial) Flow Compressor
  • 2.
    2 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR • Based on Staging: • Single Stage Compressor • Multistage Compressor Single Stage Axial Compressor • A compressor with one rotor and one stator stage. Working Principle:  Rotor imparts kinetic energy to the fluid.  Stator converts kinetic energy to pressure energy.
  • 3.
    3 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR Equations – Single Stage Compressor: Euler’s Turbomachinery Equation: Δ h0 = U⋅ΔVθ • Δh0​ : Stagnation enthalpy rise (J/kg) • U: Blade speed at rotor tip (m/s) • ΔVθ ​ : Change in tangential velocity component (m/s) Isentropic Efficiency (ηs ) = [h02−h01] / [h02s−h01] • ηis​ : Isentropic efficiency • h02​ , h01​ : Total enthalpy at outlet and inlet • h02s​ : Total enthalpy for isentropic process
  • 4.
    4 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR 6.Multistage Compressors Consists of multiple rotor-stator stages to achieve higher pressure ratios. Advantages: • Higher total pressure rise • Improved efficiency with interstage cooling Use Cases: Jet engines, industrial gas compressors
  • 5.
    5 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR Multistage Compressor Performance 1.Total Pressure Ratio = • ​ P0: Stagnation pressure • T0​ : Stagnation temperature • γ : Ratio of specific heats 2. Overall Efficiency ηoverall = (T0,exit−T0,inlet) / (Ts 0,exit​ −T0,inlet​ ​)
  • 6.
    6 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR 8: Velocity Triangles: Illustrates relative and absolute velocities at blade inlet / outlet. The figure 2, Show the Inlet and outlet velocity triangles Where • V: Absolute velocity, • U: Blade speed, • W: Relative velocity
  • 7.
    7 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR Degree of Reaction (R) = Δh rotor / Δh stage = 1/2(1−V2θ+V1θ) / U • Indicates the distribution of static enthalpy rise between rotor and stator. • Ideal for R=0.5, represents equal pressure rise in rotor and stator. Design Parameters: • Tip Mach Number (Mt), • Flow Coefficient ( ) ϕ = Vax / U • Work Coefficient (ψ) =Δh0 / U2
  • 8.
    8 FLOW COMPRESSORS -SINGLE STAGE, MULTISTAGE COMPRESSOR Losses in Compressors • Profile losses • Secondary flow losses • Tip clearance losses • Skin friction
  • 9.