Presentation on theme: "AXIAL FLOW COMPRESSORS"— Presentation transcript:
1AXIAL FLOW COMPRESSORS P M V SubbaraoProfessorMechanical Engineering DepartmentAn Efficient Way to Ingest Life in Large amount of Fluids !!!
2An Option for High Specific Speed In aero applications, the specific speed is defined as:and the flow coefficient as
3Schematic representation of an axial flow compressor It is easy to design a turbine that will work…. It requires a considerable skill to design a compressor that will work…
4Antonov An-225 MriyaThe Antonov An-225 Mriya is a strategic airlift cargo aircraft, designed by the Antonov Design Bureau in the 1980s.Payload: 250,000 kg (550,000 lb) !!!Cruise speed: 800 km/h.Altitude: 11,000 m (36,100 ft).Thrust Required: 1350 kNPower plant: 6 × ZMKB Progress D-18 turbofans.
5The Progress D-18T ( Lotarev D-18T) General characteristicsType: Three-spool high bypass turbofan engine with a single-stage fan.Fan diameter: 2.33 m (91.73 in)Dry weight: 4,100 kg (9,039 lb)ComponentsCompressor: Seven-stage IP compressor, seven-stage axial HP compressorCombustors: Annular combustion systemTurbine: Single-stage HP turbine, single-stage IP turbine, four‑stage LP turbinePerformanceMaximum thrust: kNOverall pressure ratio: 27.5Bypass ratio: 5.7Turbine inlet temperature: 1,600°KThrust-to-weight ratio: Approx 5.7:1
19Cycling of Kinetic Energy in Axial Flow Compressor
20Macro Geometric Specification of An Axial Compressor The geometry of a compressor can be categorised into 3 main designs types,A Constant Outer Diameter (COD),A Constant Mean Diameter (CMD) orA Constant Hub Diameter (CID),
21Specifications of An Axial Compressor There are several different parameters that can specify a particular compressor.The first set of input parameters are based on the running conditions for the machine.These involve mass flow, pressure ratio , rotational speed and the number of stages.Stage degree of reaction : For controlling the distribution of the load between the rotor and the stator.If this is not of importance, the outlet flow angle for the each stage must be set instead.
22Thermodynamics of An Axial flow Compressor Stage p03 = p02T03 = T02Va32/cpp3Va22/cpp2Tp01T01Va12/cpp1T1s
23Kinematics of An Axial Flow Compressor Stage Inlet Velocity TriangleOutlet Velocity Triangle
24Kinetics of An Axial Flow Compressor Stage Rate of Change of Momentum:Inlet Velocity TrianglePower Consumed by an Ideal Moving BladeOutlet Velocity Triangle
25Energy Analysis of An Axial Flow Compressor Stage Change in Enthalpy of fluid in moving blades :Inlet Velocity TriangleOutlet Velocity Triangle
26Isentropic compression in Rotor Blade Degree of Reaction of A Stage, R :
27Compressible Flow Machines Owing to compressibility of gas in a compressorThe degree of reaction for equal pressure rise in stator and rotor will be greater than 0.5.The stage total pressure rise will be higher in order to get equal static pressure rise in stator and rotor.
28Power input to the compressor : Inlet Velocity TriangleOutlet Velocity TriangleCurrent Practice:Theoretical Power input to the compressor: