请问RB211发动机和RB199发动机的核心机是同一个吗

如题：请问RB211发动机和RB199发动机的核心机是同一个吗？

还有，谁能介绍一下英国的埃汶系列军用喷气发动机情况，是单轴发动机吗？

在维基上就查到：
Specifications (Avon 301R)[edit]
Data from [13]
General characteristics
Type: Turbojet
Length: 126 in (3,200 mm)
Diameter: 35.7 in (907 mm)
Dry weight: 2,890 lb (1,310 kg)
Components
Compressor: 15-stage axial flow
Combustors: Cannular, 150 lb/s (68 kg/s)
Turbine: Two-stage axial flow
Fuel type: Kerosene
Performance
Maximum thrust: 12,690 lbf (56.4 kN)dry/16,360 lbf (72.8 kN) with reheat
Overall pressure ratio: 7.45:1
Specific fuel consumption: 0.932 lb/(lbf·h) or 26.4 g/(kN·s) (dry) 1.853 lb/(lbf·h) or 52.5 g/(kN·s) (wet) [14]
Thrust-to-weight ratio: 5.66:1 (56 N/kg)如题：请问RB211发动机和RB199发动机的核心机是同一个吗？

还有，谁能介绍一下英国的埃汶系列军用喷气发动机情况，是单轴发动机吗？

在维基上就查到：
Specifications (Avon 301R)[edit]
Data from [13]
General characteristics
Type: Turbojet
Length: 126 in (3,200 mm)
Diameter: 35.7 in (907 mm)
Dry weight: 2,890 lb (1,310 kg)
Components
Compressor: 15-stage axial flow
Combustors: Cannular, 150 lb/s (68 kg/s)
Turbine: Two-stage axial flow
Fuel type: Kerosene
Performance
Maximum thrust: 12,690 lbf (56.4 kN)dry/16,360 lbf (72.8 kN) with reheat
Overall pressure ratio: 7.45:1
Specific fuel consumption: 0.932 lb/(lbf·h) or 26.4 g/(kN·s) (dry) 1.853 lb/(lbf·h) or 52.5 g/(kN·s) (wet) [14]
Thrust-to-weight ratio: 5.66:1 (56 N/kg)