Fundamentals of Turbomachinery (eBook)

Theory and Applications

Ryoichi Samuel Amano, William W. Peng (Autoren)

eBook Download: EPUB

2025 | 2. Auflage
958 Seiten
Wiley (Verlag)
978-1-394-27355-3 (ISBN)

Infos

An accessible and up-to-date discussion of foundational turbomachine technology

In the newly revised second edition of Fundamentals of Turbomachinery: Theory and Applications, a team of distinguished researchers delivers an accessible introduction to turbomachinery, taking readers from a foundational understanding of the subject to application-ready knowledge.

The book explores basic and advanced turbomachinery technologies, including fans, blowers, and compressors, as well as gas turbines, steam turbines, hydro turbines, wind turbines, and hybrid power generation, among others. The book also covers emerging technologies in the field, such as simulation technologies, computer-assisted design, security issues, and the impact of artificial intelligence (AI) technology.

Readers will also find:

• A straightforward introduction to turbomachinery that equips students to select turbomachines in practice confidently
• Comprehensive explorations of hybrid power generation, including coverage of contemporary energy capture and storage technology
• Practical discussions of hydroelectric turbines, including Pelton, Francis, and Kaplan turbines
• Complete treatments of radial, mixed-flow, and axial flow pumps and compressors

Perfect for undergraduate and graduate students with an interest in turbomachinery, Fundamentals of Turbo­machinery: Theory and Applications will also benefit technical engineers, practicing researchers, and students at technical and junior colleges.

Ryoichi S. Amano, PhD, is an expert in turbomachinery and current energy technologies. He is the Director of the US Department of Energy funded Industrial Assessment Center for a leading institution covering the US Midwest Region. He is the Chief Editor for the International Journal of Rotating Machinery (Wiley). He also served as an associate editor for the ASME Trans-Journal of Energy Resources Technology and the Journal of Fluids Engineering. Dr. Amano's research achievements have been recognized through prestigious international awards, such as the AIAA Energy Systems Award, the ASME George Westinghouse Gold Medal, and the ASME Henry R. Worthington Medal. Dr. Amano is currently a Fellow of the Royal Aeronautical Society, a Fellow of ASME, a Fellow of ISEES, and a member of several other organizations. Dr. Amano has published four books and over 250 journal articles.

William W. Peng was a professor emeritus of mechanical engineering at California State University, Fresno. He obtained a BSME degree from National Taiwan University in 1965, an MS and a PhD in Aeronautics & Astronautics from Stanford University in 1968, and a PhD in Aeronautics & Astronautics from Stanford University in 1973. After working for eight years in the private industry, both as a turbomachine manufacturer and user, he began his academic career at Texas A&M University in 1981. Then he moved to California State University in 1984, where he taught the senior turbomachinery and graduate gas turbine classes. He had extensive experience in the design and application of centrifugal pumps and fans/blowers, gained through his regular job and consulting work with various industries.

Textauszug

1
Introduction

1.1 Definition

The word “turbo” comes from Latin, which implies spinning or whirling. A rotating blade row, a rotor, or an impeller varies the stagnation enthalpy of the fluid moving through it by doing either positive or negative work, depending upon the effect required of the machine. The turbomachine is an energy conversion device that converts mechanical energy to thermal/pressure energy or vice versa. The conversion is done through the dynamic interaction between a continuously flowing fluid and a rotating machine component. Both momentum and energy transfer are involved. Hence, positive displacement machines, such as piston‐type or screw‐type machines, which operate due to the static interaction between the fluid and mechanical components, are excluded.

Historically, the first turbomachines could be identified as water wheels, which appeared between the third and first centuries B.C. in the Mediterranean region. These were used throughout the medieval period, which began the first Industrial Revolution. A turbomachine has a rotating component that provides continuous interaction with a flowing fluid. Mechanical energy is delivered through this rotating element. Thermal/pressure energy in the flowing fluid can be in either kinetic energy or static enthalpy energy mode. These two energy modes can be converted in either direction through a diffuser or nozzle called stators, while rotating components are called rotors or impellers. Additional components are sometimes needed to direct the fluid in an appropriate direction.

1.2 Types of Turbomachines

Turbomachines can be classified according to

1. The direction of energy transfer, either from mechanical to thermal/pressure or vice versa.
2. Type of fluid medium handled, either compressible or incompressible.
3. The flow direction through the rotating impeller can be axial, radial, or mixed to the rotational axis.

A classification is presented in Table 1.1. In terms of the direction of energy transfer, the machine can be either a pumping device or a turbine. A pumping device converts mechanical energy into thermal/pressure energy. Such devices include liquid pumps, compressors, blowers, or fans. The gas‐handling devices are classified based on their discharge pressure, which will be discussed in detail in later chapters. A turbine converts thermal/pressure energy to mechanical energy. Examples are hydraulic, wind, and gas or steam turbines.

Among these machines, the fluid medium handled by the liquid pump, hydraulic turbine, fan, and wind turbine can be treated as an incompressible fluid. Hence, the change of thermodynamic properties, other than pressure, of these fluids can be ignored. In machines that handle gas or steam, the variation of thermodynamic properties, such as temperature, pressure, and density, has to be incorporated into flow and energy transfer analysis.

Table 1.1 Classification of Turbomachines.1

Depending on the direction of flow in the impeller, concerning its rotating axis, the machines can be classified as radial‐, mixed‐, and axial‐flow machines, as shown in Figure 1.1. The Francis turbine flows mostly in the mixed direction, except at discharge. In addition, the radial‐ and mixed‐flow impellers can be closed, semi‐open, or open‐type, as shown.

Figure 1.1 Types of turbomachines according to impeller type and flow direction through the impeller.

((a) Reproduced from Stepanoff, 1957/John Wiley & Sons;1 (b) Reproduced from Gibbs, 1971/Ingersoll‐Rand.2)

Further classification of turbomachines according to their mechanical arrangement is also possible. This includes the basic single stage or the combinations of multistage, single suction or double suction, horizontal or vertical axis, and so on. Examples of the diverse types of arrangements are shown in Figure 1.2. These arrangements are chosen based on compactness or convenience of installation and maintenance.

Figure 1.2 Types of turbomachines according to mechanical arrangements.

((a, b) Reproduced from Gibbs, 1971/Ingersoll‐Rand; (c) Karassik et al., 1976/McGraw‐Hill;3 (d) Turbine Data Handbook, 1987/Weir Floway.4)

Other classifications are based on inlet flow arrangements, such as full admission or partial admission, or the flow process in the rotor, either impulse (constant static enthalpy or pressure) or reaction machine. These classifications will be discussed in detail in later chapters when the individual types of machines are treated.

1.3 Applications of Turbomachines

Turbomachines are widely used in power‐generating and fluid‐handling systems. In a typical central power plant, fossil, or nuclear, as shown in Figure 1.3,5 the central component is a steam turbine, which is used to convert the thermal energy of steam into mechanical energy to drive an electric generator. Several pumps handle liquid water, including boiler‐feed, condensate, and cooling‐water circulating pumps. Turbomachines are also used in other energy‐producing systems such as hydropower, wind power, and geothermal power installations.

Figure 1.3 Typical central power plant with combined cycle.

(Courtesy of Mechanical Engineering Power magazine, Nov. 1997, page 2; © Mechanical Engineering magazine, the American Society of Mechanical Engineers.)

The other major application of turbomachines is the gas turbine engines used in aircraft and industrial power plants. Multistage axial‐flow gas turbines and compressors are exclusively used in high‐power units. Centrifugal types are used in the smaller engines of propulsion systems for ground, marine, and air vehicles. A typical case is the automotive engine shown in Figure 1.4.6 In the fluid‐handling systems found in many industries, different types of pumps, fans, blowers, and compressors are employed to pressurize and transport the liquid or gas. Typical examples are the heating, ventilation, and air‐conditioning (HVAC) systems shown in Figure 1.5,7 and water supply, water treatment, irrigation, oil production, oil refinery, gas transport, chemical process, and many other industries.

Figure 1.4 Automotive gas turbine engine.

(Reproduced with permission from Garrett/Ford AGT101 Advanced Gas Turbine Program Summary, Garrett Turbine Engine Co., Honeywell Aerospace, Phoenix, AZ.)

Figure 1.5 Turbomachines used in a typical commercial HVAC system.

(Reproduced from McQuiston et al., 2005/John Wiley & Sons.)

1.4 Performance Characteristics

As an energy conversion device, a turbomachine is characterized by several parameters. These parameters and their relationship with machine geometry and dimensions based on the principles of fluid mechanics and thermodynamics are the main topics in this text.

The main parameters that characterize a turbomachine are input and output power, rotating speed, efficiency, through flow rate and inlet, outlet fluid properties, etc. In pumping devices such as liquid pumps, fans, or compressors, the output pressure is used to overcome the friction loss in the load, which is characterized by pressure loss versus flow rate. Hence, the performance of a typical pumping device is expressed in terms of the pressure rise Δp (or head rise H) versus the volumetric flow rate Q, or mass flow rate m, at a constant rotating speed N, as shown in Figure 1.6. The operating condition varies with a throttle valve at the discharge. In most cases, the input shaft power and efficiency are also included in this diagram. The overall efficiency is defined as the ratio of output power to input shaft power:

(1.1)

where Po is the output hydraulic power (product of volumetric flow rate and pressure rise), and Ps is the shaft power (product of angular velocity and torque of the shaft), that is,

Figure 1.6 Typical pump, fan, and compressor performance curves at constant rotating speed.

For a fan or blower, the pressure rise is expressed in terms of the water head, either total or static head, and the flow rate is expressed in terms of the volumetric flow rate at the inlet since the density can vary slightly. In a compressor, the performance is normally expressed in the outlet–inlet pressure ratio p2/p1 versus the mass flow rate at a constant rotating speed. The adiabatic efficiency is expressed as the ratio of ideal enthalpy increase along the isentropic process over the actual enthalpy increase, ηad = Δhs/Δh.

At the high flow rate, the operation is limited by cavitation in pumps and choking due to shock waves in compressors. The low flow rate is limited by surging, a strong flow reversal at the inlet due to boundary layer separation. This problem is more severe in a compressor than in a pump.

The performance of turbines is also expressed in terms of head, rotating speed, output‐shaft power, efficiency, and discharge flow rate. The loads, such as an electric...

Produkt-Details

• Erscheint lt. Verlag: 8.9.2025
• Sprache: englisch
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: aerospace power generation • computer-controlled systems • current energy technology • hybrid power generation • Power Plants • Power Plant Technology • renewable energy machines • turbines textbook • turbomachinery textbook • turbomachine technology
• ISBN-10: 1-394-27355-X / 139427355X
• ISBN-13: 978-1-394-27355-3 / 9781394273553