Review of organic Rankine cycle for small-scale applications

Thermo-fluid dynamics preliminary design of turbo-expanders for ORC cycles

A novel cascade organic Rankine cycle (ORC) system for waste heat recovery of truck diesel engines

Design and performance prediction of radial ORC turboexpanders

Modelling and optimization of organic Rankine cycle based on a small-scale radial inflow turbine

Part 1: Outline of the book history and applications the centrifugal compressor the radial turbine non-dimensional parameters for performance assessment and design selection. Part 2 Fundamental fluid mechanics and thermodynamics: the basic equations the dynamics of compressible, perfect gas flow definitions of efficiency loss coefficient definitions stator performance parameters. Part 3 Preliminary design and analysis of centrifugal compressors: non-dimensional parameters for design selection application of basic thermo-fluid dynamics to compressors impeller design diffuser performance, design and analysis. Part 4 Preliminary design and analysis of radial turbines: basic design concepts preliminary design of the rotor performance correlations rotor passage preliminary design of the stator exhaust diffuser. Part 5 Generalised computer based one-dimensional performance prediction: generalised gas dynamic analysis empirical flow models and loss correlations summary of prediction procedure. Part 6 Modelling of compressor impellers with separated flow: performance prediction models application to experimentation. Part 7 Geometric description of turbomachine blades and passages: surface definition by two-dimensional projection functional representation of two-dimensional curves geometry definition by three-dimensional surfaces functional representation of three-dimensional surfaces. Part 8 Computation of internal flows: categorisation of methods calculation domains inviscid solution methods viscous solution methods coupled viscous-inviscid methods modelling of stator flows. Part 9 Special problems associated with turbomachine design and operation: compressor surge and techniques to suppress it high pressure ratio compressors pulse operation of radial turbines variable geometry stator for radial turbines special features of radial turbine rotors turbine rotor cooling size effects and scaling. Appendices: preliminary design of centrifugal compressor impellers - computer program listing, description of the computer program preliminary design of radial turbine rotors - computer program listing, description of the program a summary of the governing equations for three-dimensional fluid flow - the conservation of mass, or continuity, equation, the momentum equation, the energy equation discretisation methods - finite difference, finite element, finite volume.

Design of radial turbomachines

The paper describes a comprehensive computer aided design procedure and its use to investigate mixed flow turbines for automotive turbocharger applications. The outside dimensions of rotor and casing as well as blade angles are determined from one-dimensional design and off design calculations, the detailed blade shape from quasi-three-dimensional analysis and mechanical stressing and vibration programs, and geometric data are presented as outside views and sections of the rotor by a graphics subroutine. The procedure consists of a series of separate programs rather than a single program, so that the designer’s intervention at each stage of the process can be applied. Two mixed flow rotors were designed, manufactured and tested in a specially designed high speed dynamometer. The first was intended to achieve a substantial increase in mass flow over the reference radial rotor without loss of efficiency, while the latter was intended as a direct replacement of the reference radial rotor, but should give more favorable pulse performance when operating in conjunction with an engine due to changes in the operating map viz: a) lower tip speeds for best efficiency, and b) flatter mass flow characteristics. Both effects were predicted by analysis and confirmed by tests.

Computer Aided Design of Mixed Flow Turbines for Turbochargers

A unified one-dimensional analysis and design procedure for radial and mixed flow turbines is presented. This procedure considers the flow in all of the turbine components, including the inlet volute, nozzled or nozzleless inlet duct, rotor and exit duct. Losses are included for each component; in the stationary ducts, friction is the main loss mechanism, and in the rotor skin friction, clearance and disk friction are considered separately. Incidence losses at entry to both nozzle and rotor are calculated using one of two loss models. For each component, the procedure is to combine the equations of continuity, momentum, energy, and entropy into a single dimensionless expression for the Mach number at exit. This approach has proved possible under a wide variety of circumstances, and with its flexibility and ease of programming for solution by computer would seem to have many applications in one-dimensional ducted flow. The predicted performance of a radial inflow nozzleless turbine is compared with experimental results. The comparison is considered to be sufficiently good to confirm the validity of this approach. The results obtained with each of the two incidence loss models are compared. Each model is found to have its own advantages and fields of application.Copyright © 1976 by ASME

A. Whitfield

Papers

Design of radial turbomachines

Computer Aided Design of Mixed Flow Turbines for Turbochargers

A Unified Approach to the One-Dimensional Analysis and Design of Radial and Mixed Flow Turbines