Entire Engine Research Articles

A phenomenological model for near-nozzle fluid processes: Identification and qualitative characterisations

It is well established that emissions and inefficiencies primarily arise from localised fuel rich regions, which do not undergo complete combustion. In order to achieve significant reductions in NOx and soot, modern engines employ multiple injection and flow rate profiling strategies. However, during the end of each injection event, the needle restricts the internal flow of fuel, rapidly reducing the inertia of the emerging spray. Atomisation is inhibited and large fluid structures are released into the cylinder. Once the flow subsides, fuel films remain on the nozzle surface well into the cycle. Fuel residing in the nozzle cavities emerges as the cycles progresses, amalgamating with the spray deposited films. The surface-bound fuel presents an ideal environment for deposit forming reactions and a medium for precursors to adhere onto. In order to better understand these processes we performed measurements of injection transients inside an optical reciprocating rapid compression machine, using high-speed long-distance microscopy to obtain detailed characterisations of fuel films on the surface of an injector. We summarise our observations into a new phenomenological model which describes the uncontrolled release of fuel over an entire engine cycle. This model identifies the micro-scale processes that lead to the ejection, accumulation and vaporisation of fuel in-between injection events. Characterisation of these critical, transient processes can support mitigation strategies that inhibit pollutants and the formation of injector deposits.

Hydrogen-diesel co-combustion characteristics, vibro-acoustics and unregulated emissions in EGR assisted dual fuel engine

This work investigates the co-combustion characteristics of the hydrogen-diesel dual fuel with exhaust gas recirculation (EGR). The experiments were performed on a retrofitted duel fuel compression ignition engine for the entire engine load spectra, while the maximum hydrogen energy share in the study was 30%. Further, EGR was varied up to 10% to examine its effect on the hydrogen-diesel co-combustion and other relevant characteristics. It was found that although, hydrogen exhibit contrasting effects on the combustion at low and high loads, EGR continually degraded the peak combustion pressure. However, interestingly, the combustion’s variability improved on addition of EGR at higher loads, despite EGR’s detrimental effect on variability at lower loads. In addition, combustion noise and engine vibration were also studied with the aim to understand the effect of fuels and their combustion stability on such parameters. The relatively lower participation of hydrogen tends to reduce the vibrations, however, EGR leads to higher vibrations in the engine. The combustion noise however reduced with addition of hydrogen and EGR at lower loads. Further, the cumulative effect of EGR- hydrogen on the much unattended but harmful unregulated emissions was also investigated, and a synergy between the hydrogen addition and EGR was observed in this study. The present study showcases the key concerns as well as advantages in the EGR assisted hydrogen diesel combustion.

Effects of Different Mixture Ratios of Methanol-Diesel on the Performance Enhancement and Emission Reduction for a Diesel Engine

To improve the combustion and emission characteristics of diesel engines, methanol-diesel fuels with different mixing ratios (DM0, DM10, DM20, DM30, and DM40) were used to investigate the effects of methanol addition on the combustion and emission of a four-stroke diesel engine in terms of cylinder pressure, brake power, brake-specific fuel consumption, and nitrogen oxides, soot, and carbon monoxide emissions. Firstly, an improved entire diesel engine model was developed using AVL-BOOST software and validated by the experimental results. The results showed that the increase of methanol content in the fuel mixture had a negative impact on the performance characteristic of the diesel engine, but significantly improved the emission characteristic of the diesel engine. With the methanol ratio in the mixed fuel increased to 10%, 20%, 30%, and 40%, the cylinder pressure of the engine increased by 0.89%, 1.48%, 2.29%, and 3.17%, respectively. However, the power decreased by 3.76%, 6.74%, 11.35%, and 15.45%, the torque decreased by 3.76%, 6.74%, 11.35%, and 15.45%, respectively, and the brake specific fuel consumption increased by 3.77%, 6.92%, 12.33%, and 17.61%, respectively. In addition, with the methanol ratio in the mixed fuel increased to 10%, 20%, 30%, and 40%, the carbon monoxide emission decreased by 21.32%, 39.04%, 49.81%, and 56.59% and the soot emission decreased by 0.25%, 8.69%, 16.81%, and 25.28%, respectively. Therefore, the addition of methanol to the fuel can improve the combustion and emission characteristics of the engine.

Experimental analysis of the system behavior of a two-stage variable compression ratio (VCR) system in fired SI-engine operation

Especially for turbocharged SI engines, systems that allow to adapt the geometrical compression ratio offer advantages in terms of part load efficiency and maximum power output. In this study a conrod based two-stage VCR system with an eccentric piston pin bearing is investigated in fired engine operation by means of a specially designed measurement technique. For this purpose different sensor technologies were equipped to a VCR conrod and the oil supply system of a prototype crankshaft. The data transmission was realized by an optimized mechanical linkage system and a digital rotation telemetry system. The high-performance measurement technique presented in this paper enables a detailed analysis of the influencing parameters resulting from the fired engine operation, such as dynamic pressure stimulation in the crankshaft oil supply or the acceleration of the internal oil columns. The presented crank angle based measurement results of the system are obtained through fired testbench investigations on a three-cylinder full engine in the entire engine map, focusing on the speed range up to [Formula: see text] and loads up to [Formula: see text]. A detailed analysis of the conrod system behavior in high and low compression ratio is shown. A key finding is, that the so called “hydraulic pretension” of the support chamber is necessary to meet the requirements for a stiff force transmission in the low compression ratio stage. The in-depth investigation contributes to the build up of a comprehensive system understanding and represents a solid base to expand the development process of conrod based two-stage VCR systems.

The ultra-high efficiency gas turbine engine, UHEGT, part III: Dynamic behavior of the system in variable performance conditions

This paper investigates the dynamic behavior of an Ultra-High Efficiency Gas Turbine Engine (UHEGT) with Stator Internal Combustion. The UHEGT-technology was introduced for the first time to the gas turbine design community at the Turbo Expo 2015. In developing the UHEGT-technology, the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed in the first three HP-turbine stator rows. Noticeable improvement in the engine thermal efficiency and power along with other performance advantages are brought by this technology. In the current paper, dynamic simulation is performed on the entire gas turbine engine (UHEGT) using the nonlinear dynamic simulation code GETRAN. The simulations are in 2 D (space-time) and include the majority of the engine components including rotor shaft, turbine and compressor, fuel injectors, diffuser, pipes, valves, controllers, etc. The thermo-fluid conservation laws are applied to the flow in each component which create a system of nonlinear partial differential equations that is solved numerically. Two different fuel schedules (steep rise and Gaussian) are applied to all injectors and the engine response is studied in each case. The results show that fluctuations in the fuel flow lead to fluctuations in most of the system parameters such as temperatures, power, shaft speed, etc. However, the shapes and amplitudes of the fluctuations are different and there is a time lag in the response profiles relative to the fuel schedules. It is shown that an increase in average fuel flow in the system leads to a small drop in efficiency due to the cycle change from the design point. Moreover, it is seen that the temperatures usually rise fast with increase of fuel flow, but the system tends to cool down at a slower rate as the fuel is reduced.

Preface

ICAM 2020 Organizing Committee1,2,* 1Central Institute Aviation Motors, Russia, 111116 Moscow, Aviamotornaya, 2 2United Engine Corporation, Russia, 105118 Moscow, Budenny prospect, 16 *icam@ciam.ruThe International Conference on Aviation Motors will be held on May 18-21, 2021 in Moscow, Russia. It was originally planned to hold the conference in 2020, but it was postponed to 2021 due to the COVID-19 pandemic.ICAM is targeted on the discussion of a wide range of topical issues on the aerospace industry. About 700 participants have registered, including 320 speakers with oral presentations. There are also a significant number of research students presenting their work.The conference is traditionally organized by the Central Institute of Aviation Motors (CIAM) every five years. 2020 year also marks the 90th Anniversary of the CIAM (Moscow, Russia), that is the only scientific organization in Russia that carries out the full cycle of research activities necessary to create aircraft engines and gas turbine units based on them, as well as scientific and technical support of products in operation. Several world-class scientific schools have been created in CIAM, the works of which have determined the development of aviation industry for many decades. Among the outstanding scientists and designers who made up the pride of the Institute and the entire domestic aircraft engine development field: M.V. Keldysh, V.Ya. Klimov, A.M. Lyulka, A.A. Mikulin, B.S. Stechkin, V.N. Chelomey, G.G. Chernui, O.N. Favorsky and others.ICAM 2020 is organized with the active cooperation of the United Engine Corporation (Moscow, Russia). UEC is a vertically-integrated company producing engines for military and civil aviation, commercial programs, equipment of various strengths for generating electric and heat energy, gas pumping systems and marine gas-turbine units.There are several main research topics of the conference: Aircraft propulsion and power plants; Turbomachinery; Gas dynamics and combustion; Strength, reliability, new construction materials and technologies; Tests. Measurement systems and techniques; Automatic control and health monitoring systems; Aviation chemmotology and Compressor-free engines.We are sure that the proceedings of ICAM 2020 will serve as an important research source of the knowledge that will lead to not only scientific and engineering progress but also other new products and processes.

Development of common rail lube oil injector for large two-stroke marine diesel engines

The two-stroke crosshead diesel engines, nowadays moving the majority of merchant vessels, have lubrication systems which significantly contribute to their overall emissions, since they work on total loss basis: a relevant fraction of lubricant enters the exhaust duct, increasing total exhaust emissions. This paper demonstrates that a viable solution to reduce lubrication system related emissions can be found in the application of a new common rail type ( CR) lubrication system. Particularly, in the first part of this study, a common rail injector was simulated and numerically optimized by means of AMESim. The main parameters influencing lube oil injected mass were identified, with the purpose to design a highly time responsive injector. Therefore, a CR injector was realized and experimentally characterized by means of a dedicated test cell, defining the lube oil injection map over the entire engine load range. Finally, full scale engine tests allowed to evaluate oil loss at exhaust, proposing, and applying the Sulfur tracing methodology. A comparison with a pulse jet lubrication system demonstrated a relevant reduction in oil loss: 100% engine load testes demonstrated decreases ranging from 56.2% to 63.3%, while once fixed the lube oil feed rate to 0.8 g/kWh a maximum reduction in oil loss equal to 66.7% was reached. These results allow nominating the common rail lubrication system as a feasible solution to significantly reduce oil loss at exhaust of large two-stroke marine diesel engines.

Fully Coupled Turbojet Engine Computational Fluid Dynamics Simulations and Cycle Analyses Along the Equilibrium Running Line

Abstract This work presents fully coupled computational fluid dynamics (CFD) simulations and thermodynamic cycle analyses of a small-scale turbojet engine at several conditions along the equilibrium running line. The CFD simulations use a single mesh for the entire engine, from the intake to the exhaust, allowing information to travel in all directions. The CFD simulations are performed along the equilibrium running line by using the iterative Secant method to compute the fuel flow rate required to match the compressor and turbine power. The freestream pressure and temperature and shaft angular speed are the only inputs needed for the CFD simulations. To evaluate the consistency of the CFD results with thermodynamic cycle results, outputs from the CFD simulations are prescribed as inputs to the cycle model. This approach enables on-design and off-design cycle calculations to be performed without requiring turbomachinery performance maps. In contrast, traditional off-design cycle analyses require either scaling, calculating, or measuring compressor and turbine maps with boundary condition assumptions. In addition, the CFD simulations and the cycle analyses are compared with measurements of the turbojet engine. The CFD simulations, thermodynamic cycle analyses, and measurements agree in terms of total temperature and pressure at the diffuser–combustor interface, air and fuel mass flow rate, equivalence ratio, and thrust. The developed methods to perform CFD simulations from the intake to the exhaust of the turbojet engine are expected to be useful for guiding the design and development of future small-scale gas turbine engines.

A Concept of Hydraulic Power Transmission for Heavy Self-Propelled Mining Vehicles

The study considers a concept of hydraulic power transmission with a multi-stage hydraulic torque converter. The design objective is expanding the operational envelope of a self-propelled vehicle, increasing the power train efficiency in the entire engine torque transformation range. Two hydraulic torque converter (HTC) designs are proposed. The HTC uses uncoupled turbines (centrifugal, axial, centripetal) in a series arrangement. Each turbine operates in its optimal range of the HTC ratios. Each turbine is connected to the output shaft with individually controlled couplings. To optimize the hydraulic torque converter performance, a dedicated stator for each turbine is proposed. It is activated/deactivated concurrently with the respective turbine. The proposed hydraulic power transmission is designed for heavy self-propelled vehicles operated in mining and construction. The design can also be used in railway engine power trains to replace the complicated multistage hydraulic transmissions consisting of two or three conventional hydraulic torque converters. The hydraulic power transmission kinematics and principle of operation are protected by the Russian patent No. 2716378. The study is supported by Tula State University as research project No. 2019-22.

Numerical simulation of thermal environment in 320,000 tons VLCC engine room

The engine room is the power center of the ship, including the main diesel engine and many other equipment, to maintain the stable operation of equipment in the engine room, to provide a comfortable working environment for the crew. The temperature and humidity in the engine room must reach a certain standard. There are ventilation systems in the engine rooms of ships, but we don’t have a good way to direct the lay out of the ventilation system. This paper takes 320,000 tons of VLCC as an example, uses FLUENT software to numerically simulate the temperature field and velocity field in the engine room, obtains the temperature distribution of the entire engine room, analyzes the simulation results, and proposes a ventilation layout optimization plan. Finally, the full text is summarized and the plan for further research is discussed.

CFD를 이용한 항공용 마이크로 가스터빈 엔진 시뮬레이션

Turbojet-type micro gas turbine engine has been widely adopted for an aero-propulsion system of small-sized aircraft due to its simplicity and prominent thrust-to-weight ratio. The number of applications using micro gas turbine engine continues to grow with the development of various type in aerial vehicles. To adopt an appropriate micro gas turbine engine for a specific aero application, an evaluation of the engine performance is very important. A thermodynamic cycle analysis is an usual method for the gas turbine engine performance evaluation. Establishing the thermodynamic cycle model of turbojet engine is relatively simple and simulation time is the shortest compared to other methods. However, details of engine characteristics would not be captured with the cycle model and the result might be incorrect if analysis condition were apart from component’s operational range. These deficiencies could be compensated by taking the advantage of CFD analysis, which is capable of simulating the details of flow characteristics inside engine components such as stall, choke and shock. These flow phenomena can deteriorate engine performance or can cause severe engine failure. This paper demonstrates performance analysis of micro gas turbine engine using CFD analysis. Major components in a micro gas turbine engine, such as compressor, combustor, turbine and exhaust nozzle, were modeled and linked together to establish entire engine model. Fortran sub-routine was newly developed and embedded to CFD code, which is manipulating the fuel flow into combustor to match compressor and turbine torques. The sub-routine continues to run until it finds matching point of each component at designated rotating speed. Using this CFD model, not only engine cycle performance, but also component performance can be evaluated with a single calculation.

Smart Coordinate Measuring Machine (CMM) Inspection for Turbine Guide Vanes with Trend Line and Geometric Profile Tolerance

Turbine guide vanes are among the most critical and complex turbine parts. As an entire engine comprises a significant number of vanes, simplification of the measurement process translates into overall time and money savings. The key to simplification is to define critical areas for inspection, which enables relaxation of strict inspection standards in all areas of stable process manufacturing. The method described herein can help engineers to achieve savings in inspection time and cost, at the same time ensuring the correct shape of vanes as the approach used in this work places great emphasis on correlations between measurements, working conditions, and manufacturing abilities. Another element of the novelty of this approach is an atypical hybrid convention for the crossing of vertical and horizontal inspection paths, assuring a correlation between the measured sections. Although this novel approach was used to measure the geometry of a cast turbine guide vane, it can be easily implemented to measure the geometry of any other element of complex shape.

Self-consistent surface-temperature boundary condition for liquefying-fuel-based hybrid rockets internal-ballistics simulation

A novel methodology for the calculation of the surface temperature of liquefying fuels typically burned in hybrid rockets is proposed. This procedure stems from the formulation of a fuel in-depth pyrolysis model coupled with the resolution of the thermo-fluid-dynamic field in the rocket combustion chamber, which allows for the characterization of the unstable liquid layer formed on top of the fuel surface. The aim is the simulation of the internal ballistics of hybrid rocket engines fed by paraffin-based fuels without the need for parametrically assigning the surface temperature to match the experimental data as, indeed, required in the authors’ previous work. With the presented technique, surface temperature and fuel vaporization rate are calculated locally along the wall, and, with the integration of a liquid fuel entrainment model, which requires the tuning of just one parameter (i.e. the so-called entrainment factor), the fuel regression rate is determined. The overall numerical approach, upon the assumption that the liquid fuel is in the supercritical pressure regime, is based on the solution of the Reynolds-averaged Navier–Stokes equations for single-phase multicomponent turbulent reacting flow. A series of numerical simulations are carried out to unveil the effect of the oxygen mass flux, which allowed deriving an approximate analytical equation for the regression rate prediction. A set of hot fires of a laboratory-scale hybrid rocket are reproduced through single numerical simulations carried out on the fuel port average geometry in the burn to validate the computational model, showing deviations between the measured and predicted average regression rate less than 4.5%. In order to fairly match also the fuel consumption axial profile, transient numerical simulations over the entire engine firing are conducted with which the post-burn port shape is captured with maximum error of 8%.

Investigation on the Performance Enhancement and Emission Reduction of a Biodiesel Fueled Diesel Engine Based on an Improved Entire Diesel Engine Simulation Model

In order to improve the efficiency of the diesel engine and reduce emissions, an improved heat transfer model was developed in an AVL-BOOST environment which is a powerful and user-friendly software for engine steady-state and transient performance analysis. The improved heat transfer model considers the advantages of the Woschni1978 heat transfer model and Honhenberg heat transfer model. In addition, a five-component biodiesel skeletal mechanism containing 475 reactions and 134 species was developed to simulate the fuel spray process and combustion process since it contained methyl linolenate, methyl linoleate, methyl oleate, methyl stearate, and methyl palmitate, which are a majority component in most biodiesel. Finally, the propulsion and load characteristics of a diesel engine fueled with biodiesel fuel were investigated by the improved heat transfer model in term of power, brake specific fuel consumption (BSFC), soot and NOx emissions. Similarly, the effects of the fuel injection rate on the diesel engine’s characteristic fueled with biodiesel was studied. The result showed that the errors between experiment and simulation were less than 2%. Thus, the simulation model could predict the propulsion and load characteristics of the diesel engine. The nozzle diameter, injection pressure, and injection advance angle are significant to the injection system. Thus, it is very important to choose the injection rate reasonably.

АНАЛИЗ ТРЕБОВАНИЙ К ТВЕРДОТОПЛИВНЫМ ГАЗОГЕНЕРАТОРАМ ДЛЯ СИСТЕМ ПОДАЧИ ПОРОШКООБРАЗНОГО ТОПЛИВА РЕАКТИВНЫХ ДВИГАТЕЛЕЙ

The existing sources of the operating fluid used in aviation and rocket-space technology are analyzed. The disadvantages of inert gas cylinders used as a source of the operating fluid of the component supply system in jet engines are considered. An alternative to the gas pressure system is a low temperature solid propellant gas generator (LTGG) with a coolant. Controllable powdery components supply scheme of an air-breathing engine (ramjet) is proposed. The principle of operation of such a feeding scheme is described. To ensure the stability of the output characteristics of the LTGG, a valve system is used. The requirements for the gas source and combustion products (CP) involved in the operating process have been determined. The analysis of the existing methods of cooling the CP is carried out. It was revealed that the low-temperature solid-propellant gas generator with a powdery capacitance coolant meets the most fully the above requirements, the principle of operation, which is based on the heat transfer wave localization effect. Solid propellant with the following composition: 38 % AP + 38 % Octogen + 24 % SKI-NL is selected. The CP temperature, at a pressure in the combustion chamber of 6 MPa, is 1545 K, and the CP gas constant is 459.4 J / kg·K, the condensed phase is absent, and the water vapor content in the operating fluid does not exceed 1.6 %. The combustion of the proposed propellant produces a significant amount of combustible components – 60 % CO, 4 % H2, > 1 % CH4. The use of valves on cold gas ensures the reliability of the controlled supply system of powder components, and, accordingly, the entire engine. Based on the results of the work, conclusions were made about the correspondence of the obtained parameters of solid propellant and LTGG to all the requirements set.

Description on analyzing of forces acting on connection rod for various composite materials

Connecting rod is a significant component of entire assembly engine that acts by mediator among piston assembly and crankshaft. It's changing over the responding movement of the cylinder to turning movement of the wrench; likewise it faces a ton of tractable and compressive burdens during its life time. By and large associating poles are produced utilizing carbon steel and lately aluminum amalgams are discovering its application in interfacing bar. In this work associating bar is supplanted by aluminum and it additionally portrays the displaying and thermal examination of interfacing pole. Catia strong demonstrating programming is utilized to create the 3-D strong model of Connecting bar. Ansys programming is utilized to dissect the interfacing pole. The primary point of the project is to examine the thermal stress of connecting rod by changing material with same geometry.

ПРОЕКТИРОВАНИЕ ТЕПЛОЗАЩИТНОГО ЭКРАНА ФОРСАЖНОЙ КАМЕРЫ СГОРАНИЯ СОВРЕМЕННОГО ТРДДФСМ

In this article, the design of the heat shield of the afterburner chamber of the aircraft turbofan engine is proposed, which allows to improve its characteristics. This design makes it possible to change the material of the heat shield from deformable al-loys to heat-resistant cast alloys with higher operating temperatures and lower density. Based on this, a 3D solid-state geomet-ric model of the afterburner with an upgraded heat shield was developed. The hydraulic calculation of the afterburner and its cooling channel is carried out according to the engineering method. At the same time, the burning process in the afterburner was simulated in full forced mode using the Ansys CFX software package. The data obtained because of modeling and engi-neering calculations are analyzed and compared with each other by the flow rate of air passing through the gaps between the sections of the heat shield for its cooling. As a result of the calculation, the integral characteristics of the afterburner and the de-veloped design of the heat shield are obtained. To check the efficiency and operability of the resulting design, the refining thermogasodynamic calculations of the engine with the upgraded afterburner were carried out on two typical engine operating modes: maximum and full forced. To assess the impact of changes in the characteristics of the upgraded afterburner on the main characteristics of the turbofan engine using the DVIGw simulation system. As a result of the calculations, it is obtained that the use of a heat shield of a promising design allows you to reduce the weight of the screen itself by 9% and increase the thrust of the entire engine by 1% at maximum and full forced modes in general.

A SI engine performance parameters determination for gasoline and methane operation

The present paper presents a study whose objective is to determine the performance parameters of an external mixture formation and spark-ignition engine when running on methane fuel. The experiments were carried out using optimum adjusting parameters for engine operation on methane and gasoline fuels. The parameters measured and determined are: brake specific fuel consumption, mean effective pressure, brake power, thermal efficiency, volumetric efficiency and etc. over the entire engine speed range. An analysis of the obtained results is made, comparing the obtained effective parameters at the operation of internal combustion engines with alternative fuel - methane and traditional fuel - gasoline.

Innovation Design and Development of PET Plastic Waste Processing Machines by Extruder Method

According to the Ministry of Environment (KLH), Indonesia's average population produces 189 thousand tons of garbage per day. Of this amount, 15% is plastic waste or 28.4 thousand tons of plastic waste per day. The famous handling of plastic waste is 3R (Reduce, Reuse, Recycle). Reduce is reducing the purchase or use of goods made from plastic, especially disposable items. Reuse is the repeated use of plastic-based items. Recycle is recycling goods made of plastic. The method used in this design study is to use SolidWorks software by combining the literature study VDI221 to obtain a variant of the design results that will be used. The study results do a plastic bench machine that is integrated to produce plastic seeds, which are PET-shaped, which are extruded in a device that has been brewed. From the results of the design in the data processing and design specifications of the PET plastic waste-processing machine with the extruder method, the construction consists of several units, namely, Shredder unit, Extruder unit, Cutter unit, and Machine frame. The shredder unit serves to destroy plastic waste that is still intact in pieces before being processed in the extruder unit. The extruder unit functions to melt PET waste to be extruded using a screw. The cutter unit operates to cut processed extrusion waste into pellet granules. The engine frame is used to support the entire engine unit. The results of the Plastic Waste Extruder Machine design process with an Autodesk inventor are summarized in the following specifications: machine dimensions are 1625 mm long, 300mm wide, and 1325mm high; screw extruder uses a metering screw type with a diameter of 50.8mm (2 inches) with a length: diameter ratio of 20: 1, so the screw length is 1016mm, estimated throughput rate = 84 lb/h (42kg / h), the motor used is 5.5 PK (4 KW) with a rotation speed of 1450.

Study, Development and Prototyping of a Novel Mild Hybrid Power Train for a City Car: Design of the Turbocharger

Within a large, state-funded, Italian National Project aimed to test the feasibility of an on-the-road prototype of a mild hybrid city vehicle, one of the tasks was to conceive, design and implement an innovative turbocharger that would allow for some energy recovery. The selected vehicle is propelled by a 3-cylinder, 998 cc turbocharged engine (the 66 kW Mitsubishi-Smart W451). The idea is to implement two types of energy recovery: one via the new turbocharger and one through a standard braking energy recovery (also known as KERS). The study of the former is the object of this paper. The proposed turbocharger configuration consists of mechanically separated, electrically coupled compressor and turbine, possibly mounting only slightly modified commercial equipment to reduce construction costs. This paper reports the results of the calculation of the behavior of the new turbocharging group across the entire engine operating range and describes the preliminary design of the unit. An accurate simulation of a mixed (urban and extra-urban) driving mission demonstrates that a net saving of about 5.6% can be attained by the installation of the novel turbocharger unit.