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Modern exhaust systems contain not only a piping network to transport hot gas from the engine to the atmosphere, but also functional components such as the catalytic converter and turbocharger. The turbocharger is common place in the automotive industry due to their capability to increase the specific power output of reciprocating engines. As the exhaust system is a main heat source for the under body of the vehicle and the turbocharger is located within the engine bay, it is imperative that accurate surface temperatures are achieved. A study by K. Haehndel [1] implemented a 1D fluid stream as a replacement to solving 3D fluid dynamics of the internal exhaust flow. To incorporate the 3D effects of internal fluid flow, augmented Nusselt correlations were used to produce heat transfer coefficients. It was found that the developed correlations for the exhaust system did not adequately represent the heat transfer of the turbocharger.

Contrails and aircraft-induced cirrus clouds are reputed being the largest components of aviation-induced global warming, even greater than carbon dioxide (CO2) exhaust emissions by aircraft. This article presents a contrail model algorithm specifically developed to be integrated within a multi-objective flight trajectory optimization software framework. The purpose of the algorithm is to supply to the optimizer a measure of the estimated radiative forcing from the contrails generated by the aircraft while flying a specific trajectory. In order to determine the precise measure, a comprehensive model is employed exploiting the Schmidt-Appleman criterion and ice-supersaturation regions. Additional parameters such as the solar zenith angle, contrail lifetime and spread are also considered.

Aviation turbine fuel and diesel fuel were blended with synthetic paraffins produced via two pathways and the combustion properties measured. Both aviation and diesel fuel containing synthetics produced from the fermentation of sugars, had a linear response to blending with decreasing ignition delay times from 5.05 - 3.52 ms for F-34 and 3.84 - 3.52 ms for F-76. For the same fuels blended with synthetics produced from the fermentation of alcohols, ignition delay times were increased out to 18.66 ms. The derived cetane number of the blends followed an inversely similar trend. Additionally, simulated distillation using ASTM D2887 at high synthetic paraffinic kerosene blend ratios resulted in the recovery temperatures being incorrectly reported. In this case, higher recovery volumes were at lower temperatures than earlier recovery points i.e. T90< T50, for SIP-SPK.

When presented with new technology that removes past constraints, it is often beneficial to revisit old learning's to see if they still hold, and to understand how these can be best applied to the new technology. Brake-By-Wire (BBW) systems replace all the mechanical linkages of conventional hydraulic brake systems with ‘dry’ electrical components [2],[3]. The advent of this technology poses the possibility of revisiting conventional ABS control systems by utilizing the continuous nature that BBW offers. Presented is a BBW model based wheel slip controller using a generic continuous time Model Predictive Control (MPC) algorithm [15]. The result being the first of many steps taken in understanding the full potential that BBW systems offer.

The paper presents experimental analysis of the airflow around the differential center housing of a rear drive full-scale passenger car. The study included investigation of local airflow total and static pressure, as well as surface flow visualization. Estimation of the local airflow velocity is based on the measured pressure coefficients. The experiments were carried out at different test facilities: in a climatic wind tunnel, in a full-scale wind tunnel and on-road. Influence of side wind was modeled by the yawing of the car in the full-scale wind tunnel. The results show the asymmetrical structure of the flow in both, vertical and horizontal planes. Estimated longitudinal relative local velocity decreases from maximum Vr ≈ 0.4 at the lower surface of the center housing, to about Vr ≈ 0 above the upper surface. Side wind increases airflow velocity around the center housing within the investigated yaw range ± 20°

The design of a longitudinal stability augmentation system (SAS) for an aircraft with reduced tail size in the preliminary design phase is presented. Reducing tail size will reduce drag and weight and result in better fuel consumption, but it will reduce the level of stability. A control law is designed to give the aircraft the same stability level as that with the initial tail size. The feedback gains of the control law is computed with the equivalent stability derivative criteria of and CmαCmq . The paper also gives an overview of classical root locus and pole placement method and demonstrates that equivalent stability derivative criteria is suitable for preliminary aircraft design applications. Moreover, the control laws are also synthesized using robust control LQG/LTR which can be elaborated more in the detail design phase.

A pressure-based technique has been developed for the purpose of radiator cooling airflow measurement. The technique was effectively utilised to quantify the local time-averaged air velocity through radiator cores in a small wind tunnel. The pressure difference indicated by the technique was found to be a function of the normal component of the air velocity. This paper describes the development and use of the technique which is compact, robust and non-intrusive. By applying this technique, the airflow distribution across the radiator face has been measured for a complete vehicle in an aerodynamic wind tunnel and in an environmental chamber. Results are compared for the different test environments. The influence of airflow distribution on the Specific Dissipation (a parameter used for evaluating radiator cooling performance) is examined and results for propeller-based methods and pressure-based methods are compared.

An accurate aeroelastic assessment of powered HALE aircraft is of paramount importance considering that their behaviour contrasts the one of conventional aircraft mainly due to the use of high aspect-ratio wings with distributed propulsion systems. This particular configuration shows strong dependency of the wing natural frequencies to the propulsion distribution and operating conditions. Numerical and experimental investigations are carried out to better understand the behaviour of flexible wings, focusing on the effect of distributed electric propulsion systems. Several configurations are investigated, including a single propulsion system using an engine pod (a weight with embedded electric motor, a propeller, and the wing-attached structure) installed at selected spanwise positions, and configurations with two and three propellers.

The paper presents a novel concept of very efficient transportation engines for operation with CNG, LNG or LPG. The combustion system permits mixed diesel/gasoline-like operation changing the load by quantity of fuel injected and modulating the premixed and diffusion combustion phases for high fuel energy transfer to piston work. A waste heat recovery system (WHRS) is then recovering the intercooler and engine coolant energy plus the exhaust energy. The WHRS uses a power turbine on the exhaust and a steam turbine feed by a single loop turbo-steamer. The WHRS is the enabler of much faster warm up of the engine and further improvements of the top fuel conversion efficiency to above 50% for the specific case with reduced fuel efficiency penalties changing the load or the speed.

The paper presents a novel concept of a very efficient transportation engines for operation with CNG, LNG or LPG. The paper considers the options of single fuel design with jet ignition and dual fuel design with Diesel and gas. In the first option gas fuel is injected into the main chamber by a direct injector and ignited by jet ignition. In the second option gas fuel is injected into the main chamber by a direct injector and ignited by the direct injection of a small quantity of Diesel fuel. Injection and ignition may be tuned to control the amount of premixed and diffusion combustion to produce the best fuel conversion efficiency vs. load and speed requirements within the prescribed pressure and temperature constraints.

The paper presents a novel design for a two stroke thermal engine that delivers excellent fuel economy and low emissions within the constraints of today's cost, weight and size. The engine features asymmetrical port timing through a novel translating and rotating piston mechanism. The engine is externally scavenged and supercharged, has wet sump and oil pressure lubrication, direct injection, it is lightweight, easy to build, with minimal number of parts, low production cost, ability to be balanced and compact design. The two stroke mechanism produces a linear motion of the pistons as well as an elliptical path on the surface of the cylinder. This allows the piston to sweep as well as travel past the ports. Suitable slots around the raised lip of the piston generate the asymmetry that makes the exhaust port to open first and to close first. The inlet port remains open to complete the cylinder charging and allow supercharging. Direct fuel injection is adopted for best results.

The paper considers a novel waste heat recovery (WHR) system integrated with the engine architecture in a hybrid electric vehicle (HEV) platform. The novel WHR system uses water as the working media and recovers both the internal combustion engine coolant and exhaust energy in a single loop. Results of preliminary simulations show a 6% better fuel economy over the cold start UDDS cycle only considering the better fuel usage with the WHR after the quicker warm-up but neglecting the reduced friction losses for the warmer temperatures over the full cycle.

The paper presents a survey of the opportunities to convert compression ignition heavy duty truck engines to work on single or dual fuel modes with CNG. In one popular option, the compression ignition engine is converted to spark ignition with throttle load control and port injection of the CNG. In another option of increasing popularity, the LNG is directly injected and ignited by direct injection of pilot Diesel. This latter option with direct injection of natural gas and diesel through separate injectors that are fully independent in their operation is determined to be the most promising, as it is expected to deliver better power density and similar part load fuel economy to Diesel.

A KIA Soul was instrumented to measure the relative velocity (magnitude and yaw angle) at the front of the vehicle and in-cabin sound at a location close to the side glass near the A-pillar vortex impingement. Tests were conducted at a proving ground under a range of conditions from low wind conditions (~3 m/s) to moderate (7-8 m/s) wind speeds. For any given set of atmospheric conditions the velocity and sound data at any given position on the proving ground were noted to be very repeatable, indicating that the local wakes dominated the "turbulent" velocity field. Testing was also conducted in an aeroacoustic wind tunnel in smooth flow and with a number of novel turbulence generating methods. The resulting sounds were analyzed to study the modulation at frequencies likely to result in fluctuation strength type noise.

Wind tunnels provide a convenient, repeatable method of assessing vehicle engine cooling, yet important draw-backs are the lack of a moving ground and rotating wheels, blockage constraints and, in some tunnels, the inability to simulate ambient temperatures. A series of on-road and wind-tunnel experiments has been conducted to validate a process for evaluating vehicle cooling system performance in a high blockage aerodynamic wind tunnel with a fixed ground simulation. Airflow through the vehicle front air intake was measured via a series of pressure taps and the wind-tunnel velocity was adjusted to match the corresponding pressures found during the road tests. In order to cope with the inability to simulate ambient temperatures, the technique of Specific Dissipation (SD) was used (which has previously been shown to overcome this problem).

In this paper, a theoretical model for the calculation of Specific Dissipation (SD) was developed. Based on the model, the effect of ambient and coolant radiator inlet temperatures on SD has been predicted. Results indicate that the effect of ambient and coolant inlet temperature variation on SD is small (less than 2%) when ambient temperature varies between 10 and 50°C and coolant radiator inlet temperature between 60 and 120°C. The effect of coolant flowrate on SD is larger if there is a larger flowrate variation. Experimental results indicate that a 1 % variation at 1.0 L/s will cause about ±0.6% SD variation. Therefore the flowrate should be carefully controlled.

This paper relates to the design and development of a multi-modal UAV capable of aerial flight and underwater propulsion. A novel hybrid propulsion system has been manufactured and tested. Consisting of folding blades, the propeller has been optimized for propulsion both in air and water. The critical water to air transition phase is achieved by an additional impulsive thruster powered by a C02 cartridge. To decrease the drag in underwater cruise and reduce the potential damage when the vehicle impacts the water, a morphing wing has been developed. This consists of foam-carbon fiber lay-up constructed wings in a variable sweep configuration. The actuation of the sweep is achieved by linear servos mounted on the sleeve shaped spar. An integrated prototype is constructed, using an unconventional, anhedral horizontal stabilizers to allow clearance for the morphing wing.

Compressed natural gas (CNG) is an attractive, alternative fuel for spark-ignited (SI), internal combustion (IC) engines due to its high octane rating, and low energy-specific CO2 emissions compared with gasoline. Directly-injected (DI) CNG in SI engines has the potential to dramatically decrease vehicles’ carbon emissions; however, optimization of DI CNG fueling systems requires a thorough understanding of the behavior of CNG jets in an engine environment. This paper therefore presents an experimental and modeling study of DI gaseous jets, using methane as a surrogate for CNG. Experiments are conducted in a non-reacting, constant volume chamber (CVC) using prototype injector hardware at conditions relevant to modern DI engines. The schlieren imaging technique is employed to investigate how the extent of methane jets is impacted by changing thermodynamic conditions in the fuel rail and chamber.

Accurate and robust tracking of objects is of growing interest amongst the computer vision scientific community. The ability of a multi-sensor system to detect and track objects, and accurately predict their future trajectory is critical in the context of mission- and safety-critical applications. Remotely Piloted Aircraft System (RPAS) are currently not equipped to routinely access all classes of airspace since certified Detect-and-Avoid (DAA) systems are yet to be developed. Such capabilities can be achieved by incorporating both cooperative and non-cooperative DAA functions, as well as providing enhanced communications, navigation and surveillance (CNS) services. DAA is highly dependent on the performance of CNS systems for Detection, Tacking and avoiding (DTA) tasks and maneuvers.

One of the primary hazards associated with the operation of Unmanned Aircraft (UA) is the controlled or uncontrolled impact of the UA with terrain or objects on the terrain (e.g., people or structures). National Aviation Authorities (NAAs) have the responsibility of ensuring that the risks associated with this hazard are managed to an acceptable level. The NAA can mandate a range of technical (e.g., design standards) and operational (e.g., restrictions on flight) regulatory requirements. However, work to develop these regulations for UA is ongoing. Underpinning this rule-making process is a safety case showing how the regulatory requirements put in place ensure that the UA operation is acceptably safe for the given application and environment.