ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com BLOODHOUND SSC AMAD GEARBOX ATSM EXHAUST ASSEMBLY The following explains the AMAD exhaust assembly and some of the essential design decisions made in completing this part of the car.

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD GEARBOX INTRODUCTION/BACKGROUND : AMAD GEARBOX ASSEMBLY (Diagram explained) AMAD Gearbox (blue) ATSM control Valve. AC Generator DC Generator ATSM LH chassis Rail mount position RH Chassis Rail mount position PTO Shaft Bulkhead mount position To Jet engine Hydraulic Pump Start Air in ATSM Exhaust Air out

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD GEARBOX INTRODUCTION/BACKGROUND : WHAT IS AN AMAD GEARBOX? The AMAD (Air Mount Accessories Drive) gearbox is a piece of equipment Bloodhound are reusing from the Typhoon aircraft. It is a multifunction item and is essential in starting the jet engine and then running auxiliary systems (AC & DC generators and hydraulic pump) once the jet engine is running. AMAD GEAR BOX FUNCTIONALITY: - Starting the Jet Engine: When starting the jet engine a compressed air source is connected to the car at the ‘air start couple’ on the left hand side of the car. The compressed air is fed to the AMAD gearbox at the ATSM (the ATSM is essentially an air turbine). The compressed air rotates the turbine which in turn rotates the power output of the AMAD gearbox. The exhaust air from ATSM is fed to side of the car via the AMAD ATSM exhaust assembly. The power output from the AMAD gearbox is connected to the jet engine via the PTO shaft. This spins the jet engine up to the correct start speed allowing the engine to be fired up. -Auxiliary systems power: Once the jet is running under its own power the jet engine rotates the PTO shaft which back drives the AMAD gearbox. When the AMAD gearbox is back driven by the PTO shaft the power is directed to the AC generator, Hydraulic Pump and DC generator which are mounted on the AMAD gearbox. All of these items are used in the car. When the AMAD gearbox is being back driven by the Jet engine the ATSM exhaust is unused. The ATSM exhaust assembly is only used during Jet engine start up.

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD ASSEMBLY LOCATION & THE DESIGN PROBLEM AMAD GEARBOX LOCATION: The AMAD gearbox assembly has to be mounted circa half way down the length of the car, level with the front of the EJ200 jet engine. It has to be here as this is where the PTO shaft engages with the Jet. THE AMAD EXHAUST DESIGN PROBLEM: To design an exhaust system allowing the AMAD gearbox assembly to vent exhaust air safely away from the car’s internals whilst under jet start conditions. ABH – E0013

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD GEARBOX EXHAUST DESIGN CONSTRAINTS: AMAD Gearbox exhaust assembly design constraints: The AMAD gearbox exhaust allows the exhaust air from the ATSM to be vented safely way from the internals of the car when the EJ200 jet engine is being started. The following are design constraints that effected the design of the assembly. Compact Geometry and accessibility - The exhaust assembly has to fit in the tight space available in the car while still allowing as much access as possible. The exhaust has to connect the “Air out” from the ATSM to the side of the car. The Exhaust has to be removable to allow the upper chassis to be removed and the exhaust exit has to be covered when not in use to prevent dust/dirt entering the AMAD. The exhaust must also have a similar bore size to the original Typhoon to minimise additional back pressure in the starting system. Heat resistant - The air leaving the ATSM is hot at circa 180deg C. All exhaust components need to be able to cope with this heat so material selection is crucial. Design Flexibility - The AMAD exhaust needs to be adaptable to allow both gear box configurations to be used (Bloodhound have 2–off AMAD gearbox’s a LH and RH version which are mirror opposites of each other). Vibration Isolation - The exhaust needs to Isolate any vibrations between the AMAD gearbox and the car structure where the exhaust exits. Output pressure - The output pressure given to us from the MOD indicated that on Typhoon the exhaust pressure can be as high as circa 4bar. Unknowns: No drawings were available from the MOD regarding the geometry of the AMAD gearbox and the ATSM exhaust exit. Due to military secrecy there was also no information available on the existing clamps used on the AMAD assembly.

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD EXHAUST DESIGN SOLUTION: The following shows the final geometry for the AMAD gearbox exhaust assembly and how the design constraints were met. AMAD exhaust assembly Exhaust Assembly sits above jet fuel tank LH Chassis Rail ATSM output Exhaust exits in upper Chassis under stringer 1 AMAD gearbox assembly

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD EXHAUST DESIGN SOLUTION: The following shows the final geometry for the AMAD gearbox exhaust assembly and how the design constraints were met. Access hatch allows inspection and enables access to allow band clamp to be undone when installation and removing upper chassis LH Chassis Rail Exhaust out Doubler reinforces skin around the exhaust exit hole Turbo hose (orange) provides vibration isolation between exhaust and skin V-band clamp, allows quick and easy assembly V-band clamp 2 allows end section of exhaust to be removed when installing/removing upper chassis Hinged lockable exhaust flap to close exhaust when not in use. Hatch also seals against gasket to stop dirt ingress. Exhaust exist bolts to outer skin

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD EXHAUST DESIGN SOLUTION: Design solutions to constraints from page 5 : Compact Geometry and accessibility: i.To ensure the AMAD exhaust assembly was as compact it was routed to the side of the car taking the shortest possible route while still incorporating the necessary components. ii.To increase access and ease of installation two sets of V-band clamps were used allowing the end sections of the exhaust to be removed. iii.A lockable hinged exhaust flap prevents dust/dirt ingress when the exhaust is not in use. Heat resistant: i.The metallic elements of the exhaust are stainless steel 316L. This material is compatible with the heat requirement and is also corrosion resistant. This material is also compatible with the v-band flanges/clamps required for the connection with the AMAD gearbox exhaust which helps in manufacturing welding/fabrication of this assembly. ii.The gaskets in the assembly are silicone which have a high heat resistivity. iii.The turbo hose is made from high heat silicone with fabric reinforcement. Heat resistivity to 250deg C for prolonged use. Design Flexibility: i.The skin doubler and flap are installed on both sides of the car so if the other ‘handed’ AMAD gearbox is used the exhaust is routed to the respective side. Vibration Isolation: i.Vibration isolation is achieved by using a turbo coupler which would originally be used on a Mercedes truck. This solution works well as it has a large bore size while also having excellent heat resistivity and internal pressure capability. It is also an off the shelf item which is in expensive, tried and tested and has short lead times.

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD EXHAUST DESIGN SOLUTION: Design solutions to constraints from page 5: Output pressure : i.The tubular elements of the exhaust are made from ‘off the shelf’ preformed bends and sections of cut tube welded to form the assembly. The pressure capabilities of these items are well above the requirements of the exhaust system. ii.The turbo hose used for the pressure isolation has a 12bar minimum burst pressure. Unknowns: i.The clamping features on the ATSM exhaust exit gave a few clues on the type and size of clamp used on Typhoon. Due to military information confidentiality the defence specification v-band clamps and flanges we required were not available to purchase. Through a combination of measuring and research a civilian equivalent was eventually sources and purchased. See the information pack. Manufacture/Manufacturability: To decrease costs and lead times it’s best to manufacture/fabricate components, construct assemblies, from materials that are readily available and using manufacturing techniques that are readily available. With this in mind the following considerations were made for this assembly. The tubular sections are ‘off-the-shelf’ sizes. The bores size were matched to be as close to Typhoon spec as possible while also being compatible with the available turbo hose sizes. The material selection also had to be compatible with the flanges for the V-band clamps. The bend in the exhaust assembly are made from ‘off-the-shelf’ preformed bends. Having bends made especially in this bore size is expensive, time consuming with limited manufacturing sources available. The size were matched to the straight sections and the turbo hose.

ENGINEERING ADVENTUREwww.BLOODHOUNDSSC.com AMAD EXHAUST DESIGN SOLUTION: The gaskets were made using CNC cutting techniques which is accurate quick and relatively cheap. The exhaust flap and hatch were machined on a 3 axis CNC milling machine. The exhaust exit flange is laser cut from 316L. Fast, cost effective and accurate. The sections of the exhaust are hand welded. Conclusion: Once all items were manufactured the exhaust assembly was installed into the car and is ready for the first air start of the EJ200 jet engine.