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Space Engine Systems Inc.

Company type	Private
Industry	Aerospace
Founded	2012
Headquarters	Edmonton, Canada
Key people	Pradeep Dass (President)
Products	SSTO propulsion systems, pumps, compressors, gear boxes, Permanent Magnet Motors
Website	spaceenginesystems.com

Space Engine Systems Inc. (SES) is a Canadian aerospace company led by Pradeep Dass and is located in Edmonton, Alberta, Canada. The main focus of the company is the development of a light multi-fuel propulsion system (DASS Engine) to power a reusable single-stage-to-orbit (SSTO) and hypersonic cruise vehicle. Pumps, compressors, gear boxes, and other related technologies being developed are integrated into SES's major R&D projects. SES is collaborating with the University of Calgary to study and develop technologies in key technical areas of nanotechnology and high-speed aerodynamics.

Company history

Space Engines Systems Inc. was established in 2012 by Pradeep Dass and other investors to develop the DASS engine and related technologies in the aerospace sector. SES and the CAN-K Group of Companies work together to bring novel pumps, compressors, and gearbox systems to the aerospace industry as spin off applications. On May 10, 2012, SES publicly announced the launch of their company at the Farnborough Air Show (July 9-15, 2012). On August 6, they announced their participation in the AUVSI’s Unmanned Systems North America. SES frequently attends major international trade shows in the aerospace sector including the Paris Air Show in 2013 and the Farnborough Air Show in 2014.

DASS engine

The DASS GN 1 engine concept

The DASS engine is a pre-cooled combined cycle propulsion concept that can produce thrust over a wide range of vehicle flight Mach numbers (rest to hypersonic). Derivatives of the engine can be used for propulsion of an SSTO vehicle, long-range missiles, and hypersonic transport aircraft. The engine is being developed with the flexibility for various vehicles and mission profiles. The concept uses existing aerospace technologies, including conventional gas turbine components, and new developments in nanotechnology to overcome some of the key technical obstacles associated with overheating and fuel storage. In high-speed flight, the incoming air has a very high dynamic pressure and aerodynamic deceleration results in a rise in static pressure and temperature. Temperatures can rise above the material limits of the compressor blades in a conventional turbojet. A strategy to alleviate this problem is to place a heat exchanger downstream of the inlet in order to reduce gas temperatures prior to mechanical compression. Similar to the deep-cooled turbojet or the liquefied air cycle engine (LACE), energy extracted from the incoming air in the DASS engine is added back into the system downstream as sensible heat in the fuel stream.

The DASS engine concept improves upon the heat exchange process in multiple ways. Surface nano-coatings are placed on the internal heat exchangers to enhance convective heat transfer rates, reduce heat exchanger mass, and reduce unwanted aerodynamic blockage. Metallic nanoparticles are seeded into the intake air from the inlet cone to further enhance heat transfer. The particles act as a supplemental fuel and assist the operation of flow control devices downstream. It is known that metallic fuels have desirable storage properties in comparison to hydrogen and have excellent energy densities on a per volume basis.

The main advantage of the DASS engine over conventional rocket engines for high-speed flight is the use of atmospheric oxygen in its air-breathing mode. The specific impulse (I_sp) of air-breathing engines are superior to rockets over a wide range of Mach numbers. These gains have the potential to realize a larger payload mass fraction (e.g. 4% for NASP to LEO vs 2.6% for Soyuz-2 to LEO). The higher I_sp associated with air-breathing engines is a major motivation for the development of supersonic combustion ramjet engines. Airbreathing engines typically have a lower thrust-to-weight ratio compared to rockets. That is why the DASS engine will be powering a lifting-body vehicle. For an SSTO vehicle, reduced vehicle mass and increased payload mass fraction translates to lower operation costs. For transport, the ability to travel at hypersonic speeds drastically decreases the time required to cover long distances. The altitude at which hypersonic cruise vehicles operate is usually much higher than conventional transporters (30 km for A2 vs 13.1 km for A380). The lower air density at these higher altitudes reduces the overall vehicle drag, which further improves efficiency. Current research and development is focused on engine operation at Mach 5 cruise at an altitude of 30 km. Note that 30 km is still significantly lower than what is considered to be the edge of space (100 km) and much lower than low earth orbit (~200 km). Therefore, for the DASS Engine to operate beyond the target 30 km and Mach 5 operating conditions, the design will be modified. At higher altitudes the air density decreases and the vehicle must travel faster to achieve a sufficient inlet mass capture. At even higher altitudes, the DASS engine will need to store onboard oxidizer to be used with a rocket motor in its flow path. The target is to achieve a major component of orbital velocity when operating in the airbreathing mode before switching to the rocket mode.

The fuel being considered for the engine is a combination of hydrogen and solid nanoparticles of Boron. Hydrogen has a very high energy density per unit mass whereas Boron has a very high energy density per unit volume. The high thermal conductivity of Boron relative to air will improve heat transfer rates and the high heat capacity of hydrogen will allow for a large mass of air to be cooled. The fuel selection and hardware for injection is a topic of research.

Research

Major technology hurdles for the DASS engine are related to the implementation of nanotechnology in the engine components. In a partnership with the University of Calgary, SES will assess the feasibility of using surface nano-coatings on the heat exchangers, study the effect of nanoparticle suspensions on convective heat transfer, and assess the feasibility of using metallic nanoparticles as a supplemental fuel.

Surface nano-coatings on heat exchangers

Coating a solid body with nano-particles has been shown in the scientific literature to enhance the convective heat transfer rate from solid bodies. Several mechanisms have been proposed, including the increase in the overall surface area associated with nano-coating. Essentially, it is possible that the nanoparticles act as small scale fins, which are known to improve heat exchanger effectiveness. Since these nano-scale fins are small, the pressure drop is also much less than when compared to the pressure losses of a large scale fin. This reduces the work requirements in pumping or compressing the fluid as it passes through the heat exchanger. The presence of surface roughness associated with nanoparticle deposits also promotes mixing, which directly affects convective heat transfer.

Nanoparticle suspensions for heat transfer

The suspension of a large amount of small scale solid particles in a gas results in a large surface-area-to-volume ratio. Studies in the scientific literature have shown that there is a unique interaction between the properties of solid nanoparticles and those of carrier fluid. The end result, which is not observed with larger scale particles (i.e. micron), is the alteration of the properties of the bulk fluid. For example, Lee et al. (1999) and Wang et al. (1999) have shown, experimentally, that the suspension of 24 and 23 nm diameter CuO particles in water enhance the thermal conductivity of water by 34%. SES will investigate the potential enhancement of the thermal conductivity of gases with suspended nanoparticles.

Nanoparticle combustion

Metal powders have been considered as alternative fuels for air-breathing engines because of their large energy content per unit mass and per unit volume in comparison to liquid hydrocarbon fuels. Although hydrogen has a larger energy content per unit mass than metal fuels, hydrogen fuel needs to be stored at very high pressures, cooled cryogenically, or absorbed in other materials in order to accumulate a practical amount of mass. In contrast, metal particles can be packed and stored efficiently and safely. Since the overall rate of combustion is proportional to surface area, the use of smaller scale particles can improve combustion and increase engine performance. It has been found that nanoparticles typically have a lower melting point, ignite at lower temperatures, and have a higher burning rate than larger scale particles. Therefore, the use of a particle fuel or a particle supplement to a conventional fuel is being considered in SES’s new aero-engine design.

Specialized products and services

Working with the CAN-K Group of Companies, SES offers a selection of aerospace components and services. All manufacturing is done to AS 9100 C and ISO 9001 QA. Products include:

• Specialized planetary gear box (ultra-light) with capability to run up to 420 deg Celsius ambient temperature (tested for 45 minutes under full load without metallurgical and mechanical damage);
• High-speed gear box for turbine engines;
• Efficient and light heat exchanger;
• Liquid/multiphase twin screw and three screws pump for aerospace/space applications;
• Hydraulic multiple screw pumps for automatic torque changer or other aerospace applications;
• Drive systems with sophisticated constant velocity (CV) joints;
• Custom bearings (hydrodynamic and hydrostatic);
• High temperature bearings;
• Vacuum operational equipment (custom designed);
• Double rotor system rotating in opposite directions adaptable for helicopter applications;
• Permanent Magnet motor system adaptable for aerospace and space requirements;
• Custom light weight and high temperature materials;
• Aerospace and space sub-assemblies custom made to customer’s requirements; and
• DASS Lander for space applications.

References

Category:Single-stage-to-orbit