SBIR-STTR Award

Emerging platforms such as stealth aircraft have three to five times the heat load of legacy platforms while being limited in their ability to reject heat to the environment due to the reduction of vents, grills and inlets that create radar and infra-red hotspots. This increased heat load is the result of modern avionics, advanced mission systems; fueldraulic based vectored thrust control systems, increased use of composite structures, and larger more electric aircraft engine accessories such as generators, or environmental controls. To reduce overall fuel system temperature rise through main engine oil pumps, Turnkey Design Services of Blue Island, IL proposes to design a variable delivery, two stage fixed displacement pump for aerospace applications that has excellent metering capability due to the ability to vary stroke and speed, good thermal efficiency due to the ability to completely unload one stage.

Benefit:
The program benefit is that the main engine oil pump overall fuel temperature rise will be reduced. This in turn reduces maintenance cost of aircraft by reducing the potential of engine fuel nozzles and manifolds from clogging and increasing the life of components that rely on fuel for lubrication. Potential commercial applications include commercial aircraft that that have reduced specific fuel consumption requirements.

Keywords:
oil on demand, oil on demand, metering, Turnkey Design, variable delivery, Pump

State-of-the-art oil pumps in aircraft engines deliver a volumetric flow rate proportional to the rotor speed of the high-pressure engine core, which drive the pump via the engine gearbox. In emerging aircraft platforms, the fuel and oil systems are used to cool a variety of engine and airframe systems. The undesirable oil heating accumulates and reduces the fuels heat-sink reserve at critical flight conditions. Maximum flow rates are set to meet requirements at maximum engine power settings. At power settings less than maximum, the oil flow exceeds system requirements and as a result, parasitic losses generate additional heat due to the fact that the system circulates more oil than necessary. As a result, weight is being added to the aircraft because the thermal management system is being sized at the low power flight conditions to handle the parasitic losses. The purpose of this program is to demonstrate an engine gearbox driven, high horsepower main engine variable delivery oil system pump can be produced that will reduce system thermal output by an estimated 20% and be comparable in weight/size and reliability to current state-of-the-art pumps. The new technology being introduced mounts between the engine gearbox and pump and varies the pump speed independent of gearbox speed so that Flow On Demand can be achieved. It does not increase the overall system weight and can be used in any fuel/oil fixed displacement pump application.

Benefit:
The reduction of an aircraft overall fuel/oil system temperature rise allows heat exchanger components to be smaller in size/weight thereby improving upon fuel efficiency and reducing costs. The life of components cooled by fuel can also be increased. Applications include military and commercial aircraft main engine fuel and oil pumps.

Keywords:
Thermal Efficiency, fixed displacement, flow on demand pump, variable delivery pump, low temperature rise