Blisk

Last updated
A CNC-milled, single piece axial compressor blisk Compressor blisk on display (2).jpg
A CNC-milled, single piece axial compressor blisk

A blisk (portmanteau of bladed disk) is a turbomachine component comprising both rotor disk and blades as a single part instead of a disk assembled with individual removable blades. Blisks generally have better aerodynamics than conventional rotors with single blades and are lighter. They may be additively manufactured, integrally cast, machined from a solid piece of material, or made by welding individual blades to a rotor disk. The term is used mainly in aerospace engine design. Blisks may also be known as integrally bladed rotors (IBR).

Contents

History

Blisk manufacturing has been used since the mid-1980s. It was first used by Sermatech-Lehr (now known as GKN Aerospace [1] ) in 1985 for the compressors of the T700 helicopter engine. Since then, its use has continued to increase in major applications for both compressors and fan blade rotors. Examples include the Rocketdyne RS-68 rocket engine and the General Electric F110 turbofan.

The F-35B variant of the Joint Strike Fighter uses blisks to achieve short take-off and vertical landing. [2]

Engine manufacturer CFM International is using blisk technology in the compressor section of its LEAP-X demonstrator engine program, which has completed full-scale rig testing. [3] PowerJet SaM146 engines used on Sukhoi Superjet 100s are also equipped with blisks. [4]

General Electric's Passport (formerly "TechX") engine uses blisks for both its main 52" fan as well as for 5 of its 10 high pressure compressor stages. [5] [6] The GEnx already uses blisks in some stages.

Advantages

A model of a blisk used in a gas turbine First stage Allison axial compressor blisk.jpg
A model of a blisk used in a gas turbine

Instead of making bare compressor disks and attaching the blades later, blisks are single elements combining the two. This eliminates the need to attach the blades to the disk (via screws, bolts, etc.), thus decreasing the number of components in the compressor, while at the same time decreasing drag and increasing efficiency of air compression in the engine. The elimination of the dovetail attachment found on traditional turbine blades eliminates a source for crack initiation and subsequent propagation. [7]

Efficiency improvements of up to 8% are possible. [8]

Disadvantages

Any damage to integrally bladed rotor blades beyond minor dents requires the full removal of the engine so that the rotor may be replaced or, if possible, replacement blades welded on. Maintenance of this nature cannot be done on the flightline and often must be performed at a specialized facility. Integrally bladed rotor blades must undergo rigorous harmonic vibration testing as well as dynamic balancing to an extremely high standard, since the natural damping of the dovetail attachment of a typical turbine blade is no longer present. [7]

Process

General

Blisks can be produced with several different manufacturing processes, including CNC milling, investment casting, electro chemical machining, 3D printing, or welding. Research is being conducted to produce them using friction welding of "near net" part shapes that are then machined down to the final blisk shape. [9]

Measurement and inspection

Sample blisk in ATOS ScanBox Sample Blisk in ATOS ScanBox.jpg
Sample blisk in ATOS ScanBox

The measurement and inspection of blisks is crucial for guaranteeing engine performance carried out at the end of the manufacturing processes. Traditionally this has been achieved using tactile devices, like coordinate-measuring machines (CMM), but as geometries and requirements increase, the trend in modern factories is to carry out 3D scanning inspection systems. [10] This has advantages of the speed of measurement compared to tactile devices, whilst collecting 3D data to relate back to design characteristics. Using 3D data, parts can be catalogued in this way, often called digital twin, allowing monitoring of the product through its life-cycle.

Blisk repair using adaptive machining

Engine-run blisks pose their own set of unique requirements. After parts have been in service in the engine, noticeable amounts of damage and wear will be observed. Provided that the damage and wear are within thresholds set by the design authority, it is possible that the blisks can be repaired.

Repair of blisk components is complex and first requires an accurate 3D representation of the component. The quickest way to do this is by 3D scanning the product. [10] After the part is scanned, an STL file (stereolithograph) can be passed to a CNC code generating software such as NX CAM. The tool paths are regenerated to suit the measured geometry and not the nominally generated CAD in a process known as adaptive machining. [11]

The processes would typically involve removing part or all of a blade(s), followed by a weld back to approximate size before finishing by final machining back to the airfoil shape. [12]

Related Research Articles

<span class="mw-page-title-main">Turbofan</span> Airbreathing jet engine designed to provide thrust by driving a fan

A turbofan or fanjet is a type of airbreathing jet engine that is widely used in aircraft propulsion. The word "turbofan" is a combination of the preceding generation engine technology of the turbojet, and a reference to the additional fan stage added. It consists of a gas turbine engine which achieves mechanical energy from combustion, and a ducted fan that uses the mechanical energy from the gas turbine to force air rearwards. Thus, whereas all the air taken in by a turbojet passes through the combustion chamber and turbines, in a turbofan some of that air bypasses these components. A turbofan thus can be thought of as a turbojet being used to drive a ducted fan, with both of these contributing to the thrust.

<span class="mw-page-title-main">General Electric GE90</span> High-bypass turbofan aircraft engine

The General Electric GE90 is a family of high-bypass turbofan aircraft engines built by GE Aerospace for the Boeing 777, with thrust ratings from 81,000 to 115,000 pounds-force. It entered service with British Airways in November 1995. It is one of three options for the 777-200, -200ER, and -300 versions, and the exclusive engine of the -200LR, -300ER, and 777F. It was the largest jet engine, until being surpassed in January 2020 by its successor, the 110,000 lbf (490 kN) GE9X, which has a 6-inch (15 cm) larger diameter fan. However, the GE90-115B, the most recent variant, is rated for a higher thrust than the GE9X.

<span class="mw-page-title-main">Rolls-Royce Trent</span> Family of turbofan aircraft engines

The Rolls-Royce Trent is a family of high-bypass turbofans produced by Rolls-Royce. It continues the three spool architecture of the RB211 with a maximum thrust ranging from 61,900 to 97,000 lbf . Launched as the RB-211-524L in June 1988, the prototype first ran in August 1990. Its first variant is the Trent 700 introduced on the Airbus A330 in March 1995, then the Trent 800 for the Boeing 777 (1996), the Trent 500 for the A340 (2002), the Trent 900 for the A380 (2007), the Trent 1000 for the Boeing 787 (2011), the Trent XWB for the A350 (2015), and the Trent 7000 for the A330neo (2018). It has also marine and industrial variants like the RR MT30.

<span class="mw-page-title-main">General Electric/Rolls-Royce F136</span> Never completed engine for the Lockheed Martin F-35 Lightning II

The General Electric/Rolls-Royce F136 was an advanced turbofan engine being developed by General Electric and Rolls-Royce plc for the Lockheed Martin F-35 Lightning II. The two companies stopped work on the project in December 2011 after failing to gather Pentagon support for further development.

<span class="mw-page-title-main">Engine Alliance GP7000</span> Turbofan engine manufactured by Engine Alliance

The Engine Alliance GP7000 is a turbofan jet engine manufactured by Engine Alliance, a joint venture between General Electric and Pratt & Whitney. It is one of the powerplant options available for the Airbus A380, along with the Rolls-Royce Trent 900.

<span class="mw-page-title-main">Rolls-Royce BR700</span> Turbofan aircraft engine

The Rolls-Royce BR700 is a family of turbofan engines for regional jets and corporate jets. It is manufactured in Dahlewitz, Germany, by Rolls-Royce Deutschland: this was initially a joint venture of BMW and Rolls-Royce plc established in 1990 to develop this engine. The BR710 first ran in 1995. The United States military designation for the BR725 variant is F130.

<span class="mw-page-title-main">GE Aerospace</span> American Aircraft Engine Manufacturer

General Electric Company, doing business as GE Aerospace, is an American aircraft engine supplier that is headquartered in Evendale, Ohio, outside Cincinnati. It is the legal successor to the original General Electric Company founded in 1892, which split into three separate companies between November 2021 and April 2024, adopting the trade name GE Aerospace after divesting its healthcare and energy divisions.

<span class="mw-page-title-main">Pratt & Whitney F119</span> American low-bypass turbofan engine for the F-22 Raptor

The Pratt & Whitney F119, company designation PW5000, is an afterburning turbofan engine developed by Pratt & Whitney for the Advanced Tactical Fighter (ATF) program, which resulted in the Lockheed Martin F-22 Raptor. The engine delivers thrust in the 35,000 lbf (156 kN) class and was designed for sustained supersonic flight without afterburners, or supercruise. Delivering almost 22% more thrust with 40% fewer parts than its F100 predecessor, the F119 allows the F-22 to achieve supercruise speeds of up to Mach 1.8. The F119's nozzles incorporate thrust vectoring that enable them to direct the engine thrust ±20° in the pitch axis to give the F-22 enhanced maneuverability.

<span class="mw-page-title-main">Volvo Aero</span> Former Swedish aerospace manufacturer

Volvo Aero was a Swedish aircraft, guided missiles and rocket engine manufacturer. It became GKN Aerospace Engine Systems following the company's acquisition by British engineering conglomerate GKN during 2012.

<span class="mw-page-title-main">General Electric GEnx</span> Turbofan jet engine

The General Electric GEnx is an advanced dual rotor, axial flow, high-bypass turbofan jet engine in production by GE Aerospace for the Boeing 747-8 and 787. The GEnx succeeded the CF6 in GE's product line.

<span class="mw-page-title-main">General Electric J79</span> Axial flow turbojet engine

The General Electric J79 is an axial-flow turbojet engine built for use in a variety of fighter and bomber aircraft and a supersonic cruise missile. The J79 was produced by General Electric Aircraft Engines in the United States, and under license by several other companies worldwide. Among its major uses was the Lockheed F-104 Starfighter, Convair B-58 Hustler, McDonnell Douglas F-4 Phantom II, North American A-5 Vigilante and IAI Kfir.

<span class="mw-page-title-main">Rolls-Royce Trent 1000</span> British turbofan engine, developed from earlier Trent series engines

The Rolls-Royce Trent 1000 is a high-bypass turbofan engine produced by Rolls-Royce, one of the two engine options for the Boeing 787 Dreamliner, competing with the General Electric GEnx. It first ran on 14 February 2006 and first flew on 18 June 2007 before a joint EASA/FAA certification on 7 August 2007 and entered service on 26 October 2011. Corrosion-related fatigue cracking of intermediate pressure (IP) turbine blades was discovered in early 2016, grounding up to 44 aircraft and costing Rolls-Royce at least £1.3 billion.

<span class="mw-page-title-main">General Electric F414</span> American afterburning turbofan engine

The General Electric F414 is an American afterburning turbofan engine in the 22,000-pound thrust class produced by GE Aerospace. The F414 originated from GE's widely used F404 turbofan, enlarged and improved for use in the Boeing F/A-18E/F Super Hornet. The engine was developed from the F412 non-afterburning turbofan planned for the A-12 Avenger II, before it was canceled.

<span class="mw-page-title-main">General Electric CJ805</span> Civil series of the J79 turbojet aircraft engine

The General Electric CJ805 is a jet engine which was developed by General Electric Aircraft Engines in the late 1950s. It was a civilian version of the J79 and differed only in detail. It was developed in two versions. The basic CJ805-3 was a turbojet and powered the Convair 880 airliner, while CJ805-23, a turbofan derivative, powered the Convair 990 Coronado variant.

Nadcap is a global cooperative accreditation program for aerospace engineering, defense and related industries.

<span class="mw-page-title-main">Turbine blade</span> Aerofoil; individual component of a turbine disc

A turbine blade is a radial aerofoil mounted in the rim of a turbine disc and which produces a tangential force which rotates a turbine rotor. Each turbine disc has many blades. As such they are used in gas turbine engines and steam turbines. The blades are responsible for extracting energy from the high temperature, high pressure gas produced by the combustor. The turbine blades are often the limiting component of gas turbines. To survive in this difficult environment, turbine blades often use exotic materials like superalloys and many different methods of cooling that can be categorized as internal and external cooling, and thermal barrier coatings. Blade fatigue is a major source of failure in steam turbines and gas turbines. Fatigue is caused by the stress induced by vibration and resonance within the operating range of machinery. To protect blades from these high dynamic stresses, friction dampers are used.

<span class="mw-page-title-main">Rolls-Royce LiftSystem</span> Aircraft propulsion system

The Rolls-Royce LiftSystem, together with the F135 engine, is an aircraft propulsion system designed for use in the STOVL variant of the F-35 Lightning II. The complete system, known as the Integrated Lift Fan Propulsion System (ILFPS), was awarded the Collier Trophy in 2001.

<span class="mw-page-title-main">General Electric Passport</span> High bypass turbofan aircraft engine

The General Electric Passport is a turbofan developed by GE Aerospace for large business jets. It was selected in 2010 to power the Bombardier Global 7500 and 8000, first run on June 24, 2013, and first flown in 2015. It was certified in April 2016 and powered the Global 7500 first flight on November 4, 2016, before its 2018 introduction. It produces 14,000 to 20,000 lbf of thrust, a range previously covered by the General Electric CF34. A smaller scaled CFM LEAP, it is a twin-spool axial engine with a 5.6:1 bypass ratio and a 45:1 overall pressure ratio and is noted for its large one-piece 52 in (130 cm) fan 18-blade titanium blisk.

<span class="mw-page-title-main">General Electric GE9X</span> High-Thrust Turbofan Jet Engine

The General Electric GE9X is a high-bypass turbofan developed by GE Aerospace exclusively for the Boeing 777X. It first ran on the ground in April 2016 and first flew on March 13, 2018; it powered the 777-9's maiden flight in early 2020. It received its Federal Aviation Administration (FAA) type certificate on September 25, 2020. Derived from the General Electric GE90 with a larger fan, advanced materials like ceramic matrix composites (CMCs), and higher bypass and compression ratios, it was designed to improve fuel efficiency by 10% compared to the GE90. It is rated at 110,000 lbf (490 kN) of thrust, which is 5,000 lbf less than the GE90 highest thrust variant, the GE90-115, rated at 115,000 lbf (510 kN).

<span class="mw-page-title-main">General Electric Affinity</span> Supersonic aircraft engine design

The General Electric Affinity was a turbofan developed by GE Aviation for supersonic transports. Conceived in May 2017 to power the Aerion AS2 supersonic business jet, initial design was completed in 2018 and detailed design in 2020 for the first prototype production. GE Aviation discontinued development of the engine in May 2021. Its high-pressure core is derived from the CFM56, matched to a new twin fan low-pressure section for a reduced bypass ratio better suited to supersonic flight.

References

  1. GKN Aerospace .
  2. Zolfagharifard, Ellie (28 March 2011), "Rolls-Royce's LiftSystem for the Joint Strike Fighter", The Engineer , archived from the original on 19 December 2013, retrieved 18 April 2011.
  3. "Optioning the Future", Aviation Week & Space Technology , vol. 170, no. 10, p. 37, 9 March 2009.
  4. Burchell, Bill (2 November 2010), "Powering Up Next-Gen Engine MRO", Aviation Week[ permanent dead link ].
  5. "GE Aviation Freezes Design of Passport Engine" (Press release). GE Aviation. 2012-05-13. Retrieved 2022-05-13..
  6. "type certificate data sheet E00091EN, revision 0" (PDF). FAA. 29 April 2016.
  7. 1 2 Younossi, O; et al. (2002), Military Jet Acquisition: Technology Basics and Cost-Estimating Methodology, RAND Corporation, pp. 29–30, ISBN   0-8330-3282-8 .
  8. Croft, John (21 October 2010), "NBAA: GE TechX fan blisk is all the buzz", Flightglobal.com.
  9. "Metallics Make Comeback With Manufacturing Advances", Aviation Week, Jun 5, 2013, archived from the original on April 27, 2015, retrieved February 23, 2022.
  10. 1 2 "Blisk Measurement & Inspection using GOM, ATOS 5 for Airfoil, 3D Scanners". Archived from the original on 2020-10-29.
  11. "Overview of an Adaptive Machining Process". Archived from the original on 2016-07-25.
  12. "Rolls-Royce Blisk Repair Process". Archived from the original on 2021-01-11.