|Rear view of a BR710|
|Manufacturer||BMW Rolls-Royce |
|Bombardier Global Express |
The Rolls-Royce BR700 family of turbofan engines powers regional jets and corporate jets. It was developed by BMW and Rolls-Royce plc through the joint venture BMW Rolls-Royce AeroEngines GmbH, established in 1990. The BR710 first ran in 1995. It is manufactured in Dahlewitz, Germany. Rolls-Royce took full control of the company in 2000, which is now known as Rolls-Royce Deutschland. The military designation of the series is F130.
The BR710 comprises a 48 in (120 cm) diameter single-stage fan, driven by a two-stage LP turbine, supercharging a ten-stage HP compressor (scaled from the V2500 unit) and driven by a two-stage, air-cooled, HP turbine.
In May 2017, the 3,200 engines in service reached 10 million flying hours.
The BR715 is another twin-shaft turbofan; this engine was first run in April 1997 and entered service in mid-1999. This version powers the Boeing 717.
A new LP spool, comprising a 58 in (150 cm) diameter single-stage fan, with two-stage LP compressor driven by a three-stage LP turbine, is incorporated into the BR715. The HP spool is similar to that of the BR710.
The IP compressor booster stages supercharge the core, increasing core power and thereby net thrust. However, a larger fan is required, to keep the specific thrust low enough to satisfy jet noise considerations.
The BR725 is a variant of the BR710 with a three-stage-axial flow low pressure turbine to power the Gulfstream G650. Its prototype underwent component bench and its first full engine run in spring 2008. European certification was achieved in June 2009. The first Gulfstream G650, with BR725 engines, was delivered in December 2011.
The engine has a maximum thrust of 75.2 kN (16,900 lbf). The 50 in (130 cm) fan with swept blades is 2 in (5.1 cm) larger than the BR710, the HP axial compressor benefits from three-dimensional aerodynamics for greater efficiency and have 10 stages including five blisks to reduce weight. The BR715 inspired combustor yields a longer life and lower emissions : 80% lower smoke and unburned hydrocarbons and 35% lower NOx than CAEP 6 limits. The two-stage HP turbine have blade active tip-clearance control for more efficiency and 3D aerodynamics reduce the cooling air flow while the LP turbine have three stages instead of two. Its cruise thrust specific fuel consumption at Mach 0.85 and FL450 is 0.657 lb/lbf/h (18.6 g/kN/s). With 24 titanium blades, the BR725 has a bypass ratio of 4.2:1 and is 4 dB quieter than the predecessor BR710.
Rolls-Royce has announced that it intends to offer the BR725 for the United States Air Force's (USAF) B-52 Stratofortress re-engining, although a request for proposals has yet to be issued by the USAF. 
The Advance 2 development effort inserts new, advanced technology into existing 67 kN (15,000 lbf) class BR710 and the larger BR725 engines. An even larger engine will also be made, with a 52 in (130 cm) fan. The BR710 and BR715 main developments, the next generation of 44-89 kN (10,000-20,000 lbf) engines to be introduced in the 2020s, will have an Advance 3 core, improved engine health management, newer materials and cooling. They will also have a "blisk" fan made out of titanium, with an overall pressure ratio of 50:1. These improvements will yield a 10% thrust specific fuel consumption reduction, 50% NOx margin improvement, 99.995% reliability and a 20% better thrust-to-weight ratio.
The Pearl engine was developed in Dahlewitz from the BR700 with Advance2 technologies.EASA certification was applied for on 28 February 2015. It made its first ground run in 2015, type tests in 2016 and flight tests in 2017. Six test engines logged over 6,000 cycles on 2,000 test hours. The test program included lightning strike, water ingestion, ice, and -40°C cold-start testing.
EASA certification was granted on 28 February 2018 and it was unveiled on 28 May 2018. It was undergoing flight tests in May 2018 for an end of 2019 planned entry into service aboard the Bombardier Global Express 5500 and 6500 developments. It should have logged 10,000 hours by then.
Its layout is similar to the BR.725, with the same stage count and 24 titanium fan blades. Its fan has a 48.5 in (123 cm) diameter. The enhanced 3-stage LP turbine with advanced high temperature materials, advanced segments and seals allow for higher pressures and temperatures and the new low emissions cooled combustor includes a new tiled combustion chamber. Its core uses advanced nickel alloys and ceramic coatings, includes a new 10-stage HP compressor with 6 titanium blisks and a new 2-stage HP turbine with enhanced aerodynamics and blade cooling, enhanced segments and seals.
Its overall pressure ratio attains 43:1 and its bypass ratio 4.8:1. The HP compressor ratio rises to 24:1. It delivers up to 9% more thrust with 15,125 lbf (67.28 kN) and a 7% TSFC improvement while being 2 decibels quieter.Health monitoring should improve on the BR710 99.97% dispatch reliability which is logging one unplanned engine removal per 100,000 hours while the BR715 is approaching zero unplanned removals.
The Pearl 700 will power the Gulfstream G700, a stretch of the previous G650. Evolved from its BR725 with a similar architecture plus a fourth low-pressure turbine stage and a 2 in (5.1 cm) larger, 51.8 in (132 cm) blisk fan, its bypass ratio is higher than 6.5:1 and its overall pressure ratio should exceed 50:1. It should provide 18,250 lbf (81.2 kN) of thrust, 3-5% better thrust specific fuel consumption, reduced emissions and lower noise.
The BR715 thrust ratings can be adjusted by changing a plug in the FADEC controller, meaning no engine change is required. The A1-30 can become a C1-30 with a simple plug and software change.
|Model||BR700-710A1/A2/C4||BR700-715||BR700-725A1||BR700-710D5-21 (Pearl 15)||Pearl 700|
|Configuration||1 fan, 10 HPC, 2 HPT, 2 LPT||1 fan, 2 LPC, 10 HPC, 2 HPT, 3 LPT||1 fan, 10 HPC, 2 HPT, 3 LPT||1 fan, 10 HPC, 2 HPT, 4 LPT|
|Thrust||68.4 kN (15,400 lbf)||95.33 kN (21,430 lbf)||75.2 kN (16,900 lbf)||67.8 kN (15,200 lbf)||81.2 kN (18,250 lbf)|
|Dry Weight||1,818.4 kg (4,009 lb)||2,085 kg (4,597 lb)||1,635.2 kg (3,605 lb)||1,828.8 kg (4,032 lb)|
|Thrust / Weight||3.84||4.66||4.69||3.77|
|Length||4,669 mm (183.8 in)||3,738 mm (147.2 in)||3,297 mm (129.8 in)||4,809 mm (189.3 in)|
|Rotor RPM||LP: 6,096, HP: 16,661||LP: 6,096, HP: 16,661||LP: 6,096, HP: 16,661||LP: 7,431, HP: 19,000|
|Fan Diameter||48 in (122 cm)||58 in (147 cm)||50 in (127 cm)||48.5 in (123 cm)||51.8 in (132 cm)|
|Overall pressure ratio||43:1||>50:1|