Turbocharger

There are three certain problems in automotive applications that cause environmental effect, cost and comfort problems. Therefore, internal combustion engines are required to have not only a high specific power output but also to release less pollutant emissions. For these reasons, current light and medium duty engines are being highly turbocharged because of having negative environmental effects of internal  combustion engines. Due to mentioned facts, there are studies going on to improve internal combustion engine performance. Studies for supercharging systems are also included in this range. One of the most important problems faced in supercharging systems is that air density is
decreasing while compressing air. Also air with high temperature causes pre-ignition and detonation at spark ignited engines. Various methods have been developed to cool down charge air which is heated during supercharging process. One of these methods is to use a compact heat exchangers called as intercoolers to cool charging air. The purpose of
an intercooler is to cool the charge air after it has been heated during turbocharging. As the air is cooled, it becomes denser, and denser air makes for better combustion to produce more power. Additionally, the denser air helps reduce the chances of knock. In this study, the intercooling concept was introduced and performance increase of a vehicle by adding intercooling process to a conventional supercharging system in diesel or petrol engine was analytically studied. Pressure drops, air density and engine revolution were used as input parameters to calculate the variation of engine power output. Also, possible downsizing opportunities of the cylinder volume were presented. It is found that the engine power output can be increased 154% by ideal intercooler while single turbocharger without intercooler can only
increase 65%. Also a meaningful 50% downsizing of the cylinder volume possibility achieved by means of turbocharging and intercooling. Finally, future study needs about cycle characteristics of internal combustion engines with intercooling process and intercoolers were discussed

Product safety is a fundamental requirement that every customer takes for granted. Therefore, MAN Energy Solutions is committed to meeting and upholding the highest standards for safety and reliability of its products. For turbochargers product safety is primarily associated with containment safety. It implies that in the rare case of a breakdown, as for instance a compressor or turbine wheel burst, any potential harm to the operating personnel and the surrounding machinery must be prevented.

When designing and developing turbochargers for containment safety, MAN Energy Solutions utilizes tools that are comparable to those being used by the automotive, aircraft or defense industry. For more than 15 years, MAN Energy Solutions is working on the development of numerical methods and experimental testing procedures to comply with the prevailing rules and legislation. In collaboration with experts from the VW Group and external partners the established tools are continuously improved and refined with the overarching goal of optimizing the development efforts without compromising for containment safety.

This paper presents a comprehensive methodology used by MAN Energy Solutions to design current and future generations of turbochargers for containment safety. Following the same principles as for example vehicle crashworthiness design, this methodology combines sophisticated numerical analyses with extensive experimental testing. Starting with a reference frame size of a generic turbocharger series, non-linear explicit finite element analyses are performed to explore the detailed design space and to assess and optimize the containment safety for several load cases and geometrical variants. The numerical analyses are accompanied by a comprehensive verification and validation procedure, in which the reliability of the numerical model is assessed by means of component and full-scale containment testing. The verified and validated model is then used to evaluate and certify the containment of the reference as well as the remaining frame sizes of the
generic turbocharger series without the need for hardware testing of scaled designs.

Furthermore, the paper addresses some key issues and challenges when it comes to numerical and experimental containment analysis of turbochargers. On the numerical side, a brief presentation of current state-of-the-art modeling techniques to accurately predict the complex deformation and failure behavior of components in the event of a compressor or turbine wheel burst is given. On the experimental side, light is thrown on operation in overspeed conditions, reproducible burst
mechanisms, test instrumentation and interpretation of the test results.

The scarcity of oil and gas reserves and the global warming phenomenon both urge the automotive industry toward a decrease in fuel consumption and thus a reduction in CO2 emissions. These factors will also determine the future Research and Development trends for Internal Combustion engines. The twenty first century started with many downsizing applications. Downsizing of ICE means simultaneous decreasing the displaced volume (usually by reducing the number of cylinders) and increasing the indicated mean pressure (IMEP) by means of turbocharger. This allows the preservation of power and torque performance while decreasing the engine size. As a result, the mechanical and thermal losses are reduced, the engine becomes lighter, leading to a drop in the overall weight of the vehicle, and the engine operates within its optimum fuel consumption zone.
The downsizing of internal combustion engines is already recognized as a very suitable method for the concurrent enhancement of fuel economy and lowering of CO2 and NOx emissions. In this report, downsizing is introduced as an even higher stage of development of Internal combustion engines. This important trend in the engine has been constantly developed. The existing trends and the future of downsizing engines have been considered in the report. The downsizing impacts on the fuel economy and emission were analyzed. The main goal of downsizing is to reduce CO2 emissions, increase fuel efficiency, and cut weight. The use of boosting device like turbochargers along with other technologies like direct fuel injection and variable valve timing enable the reduction in size without the loss of power and performance.

Cuprins:
I. MODUL DE FUNCŢIONARE A SISTEMULUI DE SUPRAALIMENTARE AL MOTORULUI...............................................................................................................3
II. DESCRIEREA FUNCŢIONĂRII TURBOCOMPRESORULUI CU GEOMETRIE VARIABILĂ..................................................................................................................5
III. MANAGEMENTUL FUNCŢIONĂRII TURBOCOMPRESORULUI.............................10
IV. DIAGNOSTICAREA FUNCŢIONĂRII TURBOCOMPRESORULUI...........................20
V. BIBLIOGRAFIE.........................................................................................................39

To meet the future engine emission legislations and efficiently use the fuel, automotive industries are downsizing the engine and depending on the turbocharger to deliver the high power when necessary. However, the design of a turbocharger compressor is very complex due to the transient nature and the high flow velocity and compressibility of the airflow. Modelling the airflow in the compressor requires high computation resources which could be challenging especially, when examining operating conditions that are close to surge and choke limits [1,2]. Different level of CFD complexity can be used depending on the level of details needed and objective of the study [3]. To ensure the assumptions made is not affecting the results, experimental testing using either in-house or commercial test facilities are commonly employed [2]. Various design parameters can affect the compressor performance and its range of operations [4,5]. Among these variables the inlet vane angle which can be varied to achieve high performance at various rotational speeds [6,7]. In this work, 3-D CFD model has been developed to simulate the airflow under steady operating conditions. The model utilizes RANS together with k- turbulence model to evaluate the compressor performance at various impeller rotational speed 60,000 to 140,000 rpm and inlet mass flow rates. Experimental test rig using continuous steady flow has been employed to validate the CFD model and reasonable agreement has been achieved. The effect of three design parameters (impeller leading-edge angle, impeller trailing-edge angle, splitter blade length) are examined and the effect of their deviation from its optimum value on the performance of the turbocharger compressor in terms of pressure boost, efficiency and range of the turbocharger are evaluated.

El uso de compresores y turbinas centrifugas en la industria aeronáutica es limitada, sin embargo, es importante tener conocimiento de cómo operan y sus principales aplicaciones. En este proyecto se construyó un compresor centrífugo con alabes hacia adelante, asemejando la configuración de un turbocompresor; con el fin de realizar pruebas que permitan marcar y analizar las líneas de flujo a través de los alabes del rodete. Así mismo, se realizó un programa en Matlab que permita determinar analíticamente dichas líneas observadas, bajo ciertas condiciones fijas.

This paper presents a brief overview and technical highlights of the research efforts and studies on rotary engines over the last several years at the NASA Lewis Research Center. The review covers the test results obtained from turbocharged rotary engines and preliminary results from a high performance single-rotor engine. Combustion modeling studies of the rotary engine and the use of a Laser Doppler Velodmeter to confirm the studies are d1s-cussed. An In-house program 1n which a turbocharged rotary engine was 1n-stalled 1n a Cessna Skymaster for ground test studies 1s also covered. Details are presented on single-rotor stratlfled-charge rotary engine research efforts, both In-house and on contract.

NASA TM-83699  1984  27 pages
Engines by Curtiss-Wright, OMC, Mazda

> Content ...
  » Summary + Introduction  2
  » Why a Rotary Aircraft Engine  3
  » Lewis Contract Efforts  4
  » Lewis In-House Research Programs  4
  » Outboard Marine Corporation (OMC) Engine  4
  » Turbocharged Rotary Engine Tests  5
  » High Performance Single Rotor Engine Program  6
  » Material Research for Advanced Rotary Engines  6
  » Ground Test Aircraft Program  7
  » Rotary Engine Combustion Process Research  8
  » Summary  8
  » References  9
  » Figures  11

german keywords: Wankelmotor / Kreiskolbenmotor
English Keywords: Wankel Engine / Wankel Rotary Engine / Rotary Piston Engine / Rotary Combustion Engine

2000'li yılların başından itibaren içten yanmalı motorlar daha küçük hacimde, daha
verimli ve daha az emisyona sahip olacak şekilde geliştirilmektedir. Yeni nesil motor
teknolojilerinin büyük çoğunluğunda aşırı doldurma sistemleri kullanılmaktadır. Aşırı
doldurma sistemlerinden bir tanesi de turboşarj sistemleridir. Egzoz gazlarının enerjisini
kullanarak çalışan turboşarj sistemleri, küçük ve hafif bileşenlerden oluşmakta ve çeşitli aşırı
doldurma uygulamaları arasında yaygın biçimde yer almaktadır.
Bu çalışmada, turboşarj sistemlerinin çalışma prensiplerini ve avantajlarını
vurgulamak amacı ile iki farklı tip motor için turboşarjlı ve turboşarjsız çalışma şartları teorik
olarak analiz edilmiştir. Yapılan analizde motor devri, atmosfer basıncı ve motor hacminin
farklı değerleri için teorik hesaplamalar yapılmış, hesaplamalar sonucunda motor güçleri ve
güç artışları belirlenmiştir. Turboşarjlı ve turboşarjsız motorlar için elde edilen motor güçleri
farklı turboşarj sistemlerine, motor büyüklüklerine ve coğrafi yüksekliklere göre
karşılaştırılmıştır. Turboşarj sistemleri ile % 30 -80 aralığında güç artışları bulunmuştur.

2000'li yılların başından itibaren içten yanmalı motorlar daha küçük hacimde,
daha verimli ve daha az emisyona sahip olacak şekilde geliştirilmektedir. Yeni nesil
motor teknolojilerinin büyük çoğunluğunda aşırı doldurma sistemleri
kullanılmaktadır. Aşırı doldurma sistemleri ise çalışma prensiplerine göre
kategorilere ayrılmaktadır. Aşırı doldurma sistemlerinin faydalarını korumak ve eksik
kalan yönlerini düzeltmek için çeşitli çözümler geliştirilmektedir. Bu çözümlerden
önemli bir tanesi ise aşırı doldurma sistemlerine eşlenen ara soğutuculardır.
Bu çalışmada, aşırı doldurma sistemleri ve ara soğutucularla ilgili teorik bilgi
verilmiş ve literatür taranmıştır. Ayrıca aşırı doldurma sistemlerinin etkisini
incelemek için içten yanmalı motora sahip bir aracın aşırı doldurma sistemlerindenturboşarja sahip olduğu ve olmadığı durumlar teorik olarak analiz edilmiştir. Yapılan
analizde motor devri, atmosfer basıncı ve motor hacminin farklı değerleri için teorik
hesaplamalar yapılmış, hesaplamalar sonucunda motor güçleri ve güç artışları
belirlenmiştir. Turboşarjlı ve turboşarjsız durumlar için elde edilen motor güçleri
farklı kompresör sıkıştırma oranlarına, motor büyüklüklerine, motor hızlarına ve
coğrafi yüksekliklere göre karşılaştırılmıştır. Turboşarj sistemleri ile % 30 -80
aralığında güç artışları bulunmuştur.

by Charles Jones (Curtiss-Wright), Phillip R. Meng (NASA), David R. Ellis (Cessna) 1983
86 pages (you may compare it e.g. with NASA TM-85428)

> Content ...
  » Abstract  1
  » Introduction  2
  » The Stratified Charge Rotary Engine  5
  » Rotary Aircraft Engine Background  5
  » The Direct Injected Stratified Charge Engine  8
  » Stratified Charge Rotary Rationale  8
  » Background  11
  » RC1-60 Testing  13
  » Alcohol Feasibility  15
  » RC1-350 Testing  16
  » Improved Combustion Efficiency through Turbocharging  19
  » Feasibility Testing Results - 60 Cubic Inch Module  20
  » Second Phase, Turbocharging Feasibility Testing, 350cc Module  23
  » Advanced Stratified Charge Rotary Engines  25
  » High Speed Injection  25
  » Seal Durability  25
  » Thermal Insulation for reduced Coolant + Oil Heat Rejection  28
  » Higher Strength Alloys  29
  » Turbochargers  29
  » Specific Engine Choices for General Aviation  29
  » Engine / Airframe Integration Studies performed by Cessna Aircraft  32
  » Missions + Performance Constraints  32
  » The Sizing Process  34
  » Baseline Airplanes  35
  » Rotary powered Airplanes  36
  » Comparative Results  37
  » Concluding Remarks  38
  » Commuter Aircraft Engine  39
  » Closure  41
  » References  42
  » RC2-75 Aircraft Engine Prototype  45
  » Curtiss-Wright Rotary Combustion Engine - Stratified Charge Model RC2-350  47
  » Air-Cooled Stratified Charge RC2-90 Engine (1966)  48
  » RC2-60U10 Liquid-Cooled Stratified Engine (1965)  49
  » Dual Injector Rotor Housing Configuration  50
  » Comparison Data - BSFC vs BMEP - RC1-60  51
  » Comparison of SCRC 1-60 with Volkswagen 6 cylinder Diesel  52
  » ISFC vs IMEP - RC1-60  53
  » RC1-60 Performance  54
  » ISFC vs IMEP - RC1-60 + RC1-350  55
  » BSFC vs BMEP - RC1-60 + RC1-350  56
  » ISFC vs F/A Ratio - RC1-350  57
  » Theoretical Turbocharging Effects on BSFC  58
  » RC1-60 Stratified Charge PP  59
  » Measured Reduction in Thermal + Pressure Loads from lower Compression Ratio
      + higher Air/Fuel Ratio - SCR 1-60  61
  » Curtiss-Wright RC1-350 Turbocharged Stratified Charge Rotary Combustion Engine  62
  » RC2-32 Highly Advanced Rotary Aircraft Engine - Estimated Performance  64
  » Performance Constraints on Carpet Plot of constant Payload Range  66
  » Baseline Single Aircraft  67
  » Baseline Twin  68
  » Rotary Single  69
  » RC2-32 Highly Advanced Rotary Engine - Single Engine Installation Concept  70
  » Rotary Twin  71
  » RC2-32 Highly Advanced Rotary Engine - Twin Engine Installation Concept  72
  » Wright Aircraft Engine Performance  73
  » Displacement per Rotor - in³  78
  » Engine Dimensions vs Displacement per Rotor  79
  » Rotary Engine - Weight vs Horsepower  80
  » Integral Prop Reduction Gear Box - Length + Weight vs Output Torque  81
  » Basic Engine Data - 250 Cruise HP at 25,000 Ft.  82
  » Airplane Comparisons - Single Engine + Twin Engine  83
  » Geometric Data - RC4-41 + RC6-122  84
  » 1200 BHP RC4-81 - Operating Data Summary  85
  » 2000 BHP RC6-95 - Operating Data Summary  86

german keywords: Wankelmotor / Kreiskolbenmotor
English Keywords: Wankel Engine / Wankel Rotary Engine / Rotary Piston Engine / Rotary Combustion Engine

The main work of this project is to use of turbocharger instead of using belt drive mechanism from engine to AC compressor. As we all know that when we use AC system at the same time when engine is started because of that the engine fuel efficiency get decreases. So to maintain the fuel efficiency of engine we were developing this system for cars as well as for the commercial vehicle.

To meet the future engine emission legislations and efficiently use the fuel, automotive industries are downsizing the engine and depending on the turbocharger to deliver the high power when necessary. However, the design of a turbocharger compressor is very complex due to the transient nature and the high flow velocity and compressibility of the airflow. Modelling the airflow in the compressor requires high computation resources which could be challenging especially, when examining operating conditions that are close to surge and choke limits [1,2]. Different level of CFD complexity can be used depending on the level of details needed and objective of the study [3]. To ensure the assumptions made is not affecting the results, experimental testing using either in-house or commercial test facilities are commonly employed [2]. Various design parameters can affect the compressor performance and its range of operations [4,5]. Among these variables the inlet vane angle which can be varied to achieve high performance at various rotational speeds [6,7]. In this work, 3-D CFD model has been developed to simulate the airflow under steady operating conditions. The model utilizes RANS together with k- turbulence model to evaluate the compressor performance at various impeller rotational speed 60,000 to 140,000 rpm and inlet mass flow rates. Experimental test rig using continuous steady flow has been employed to validate the CFD model and reasonable agreement has been achieved.  The effect of three design parameters (impeller leading-edge angle, impeller trailing-edge angle, splitter blade length) are examined and the effect of their deviation from its optimum value on the performance of the turbocharger compressor in terms of pressure boost, efficiency and range of the turbocharger are evaluated.

NASA TM 82772 (same content as SAE paper 820354), 1982, 24 pages
Authors: P.R. Meng, D.P. Pringle, W.J. Rice, Harold J. Schock

Engine: (old) Mazda 12A

> Content ...
  » Introduction  3
  » Facility + Instrumentation  4
  » Description of Facility  4
  » Special Instrumentation  6
  » Test Procedure  7
  » Effect of Boost  8
  » Coolant Temperature Effect on BSFC  8
  » Effect of A/F Ratio on BSFC at Cruise Conditions (105 bhp / 78.3 kW)  9
  » Diesel vs. Rotary Engine Energy Usage  10
  » Summary + Conclusions  13
  » References  15
  » Tables  17
  » Figures  18

german keywords: Wankelmotor / Kreiskolbenmotor
English Keywords: Wankel Engine / Wankel Rotary Engine / Rotary Piston Engine / Rotary Combustion Engine

This paper presents the mechanical details regarding a new control test rig for laboratory use. A variable geometry turbocharger is this system central part. In this paper it will be shown how this rotating machine can be decoupled from the internal combustion engine and fitted in a testbench where a computer emulates the vehicle’s motor. In order to accomplish this, a dozen of mechanical parts were designed and built. In addition, a set of sensors and actuators was adapted to the system. This article will show the final result of a system that will be used to test several different control strategies, with relevance given to the coefficient diagram method.

2019  18 pages  61 diagrams

Table of Content
Introduction    1
  1 » k-factor (4 charts)    2
  2 » Compression Ratio (5 charts)    3
  3 » Comparison of Heat Transfer, Crevice Volume + Leakage Area (7 charts)    4
  4 » Heat Transfer + Leakage (1 chart)    6
  5 » Heat Transfer + Crevice Volume (2 charts)    6
  6 » Leakage (10 charts)    7
  7 » Combustion Duration (11 charts)    9
  8 » Super or Turbo Charging (10 charts)    12
  9 » Insulation of Rotor Flanks (3 charts)    14
10 » Exhaust Gas Pressure (1 chart)    15
11 » Inertia of rotating Mass (1 chart)    15
12 » Type of Rotor Recess – MDR + LDR (4 charts)    16
13 » Apex Seals (2 charts)    17
14 » Mentioned Parameters / Properties + Diagram Numbers    18

german keywords: Wankelmotor / Kreiskolbenmotor
English Keywords: Wankel Engine / Wankel Rotary Engine / Rotary Piston Engine / Rotary Combustion Engine

Her araç şüphesiz sahibi için çok değerlidir. Her araç sahibi aracına çok iyi bakmayı hedeflemektedir. Araç sahipleri, araçlarının boyasından farlarına, koltuklarından direksiyonuna, motorundan turbo suna kadar her şeyiyle özenle ilgilenmesi gerekmektedir. Düzenli bakımlarını yaptırarak olası arızalara karşı hazırlıklı olmalıdır. Düzenli bakım her araç için çok elzem bir durumdur. Araçlara düzenli bakım yapılmazsa daha kötü sonuçlar ortaya çıkabilir. Çoğu araç kullanıcısı araçlarına düzenli bakım yaptırmayı gereksiz görür. Bir servise götürüp aracın hiçbir sorunu yokken bakım yaptırmayı ve ücret ödemeyi fazlalık olarak görürler. Fakat bu düzenli bakımlar yapılmazsa araçlara çok daha fazla ücret ödemek zorunda kalınabilecek hasarlar gelebilir. Bunu önceden ön görüp düzenli bakımların aksatılmaması gerekir.

Low Power is an extremely important issue for future mobile communication systems; The focus of this paper is to implementat turbo codes for low power solutions. The effect on performance due to variation in parameters like frame length, number of iterations, type of encoding scheme and type of the interleave in the presence of additive white Gaussian noise is studied with the floating point model. In order to obtain the effect of quantization and word length variation, a fixed point model of the application is also developed.. The application performance measure, namely bit-error rate (BER) is used as a design constraint while optimizing for power and area coverage. Low power Optimization is Performed on Implementation levels by the use of Voltage scaling. With those Techniques we can reduced the power 98.5%and Area(LUT) is 57% and speed grade is Increased .This type of Power maneger is proposed and implemented based on the timing details of the turbo decoder in the VHDL model.

An acoustic one-dimensional compressor model has been developed. This model is based on compressor map information and it is able to predict how the pressure waves are transmitted and reflected by the compressor. This is later on necessary to predict radiated noise at the intake orifice. The fluid-dynamic behavior of the compressor has been reproduced by simplifying the real geometry in zero-dimensional and one-dimensional elements with acoustic purposes. These elements are responsible for attenuating or reflecting the pressure pulses generated by the engine. In order to compensate the effect of these elements in the mean flow variables, the model uses a corrected compressor map. Despite of the fact that the compressor model was developed originally as a part of the OpenWAM™ software, it can be exported to other commercial wave action models. An example is provided of exporting the described model to GT-Power™. The model has been validated using experimental results obtained in a turbocharger test bench under pulsating flow conditions. The characteristics of the pressure waves (amplitude, frequency and mean flow) are similar to those of the pulses that the compressor undergoes when working coupled to a reciprocating internal combustion engine. This facility allows wave decomposition upstream and downstream of the compressor. The experimental pressure waves have been compared versus the results provided by the model analyzing both in frequency domain and in time domain in the two codes used to host the model. Finally, a comparison between the proposed 1D-0D model, which furthermore applies the compressor map, and the standard methodology used by GT-Power™, which directly only interpolates in the compressor map, has been performed. Results show better performance in the case of the proposed model and evidence the interest for the compressor geometrical description.

ÖZET 2000'li yılların başından itibaren içten yanmalı motorlar daha küçük hacimde, daha verimli ve daha az emisyona sahip olacak şekilde geliştirilmektedir. Yeni nesil motor teknolojilerinin büyük çoğunluğunda aşırı doldurma sistemleri kullanılmaktadır. Aşırı doldurma sistemlerinden bir tanesi de turboşarj sistemleridir. Egzoz gazlarının enerjisini kullanarak çalışan turboşarj sistemleri, küçük ve hafif bileşenlerden oluşmakta ve çeşitli aşırı doldurma uygulamaları arasında yaygın biçimde yer almaktadır. Bu çalışmada, turboşarj sistemlerinin çalışma prensiplerini ve avantajlarını vurgulamak amacı ile iki farklı tip motor için turboşarjlı ve turboşarjsız çalışma şartları teorik olarak analiz edilmiştir. Yapılan analizde motor devri, atmosfer basıncı ve motor hacminin farklı değerleri için teorik hesaplamalar yapılmış, hesaplamalar sonucunda motor güçleri ve güç artışları belirlenmiştir. Turboşarjlı ve turboşarjsız motorlar için elde edilen motor güçleri farklı turboşarj sistemlerine, motor büyüklüklerine ve coğrafi yüksekliklere göre karşılaştırılmıştır. Turboşarj sistemleri ile % 30-80 aralığında güç artışları bulunmuştur.

Araç turbosu çok katmanlı bir yapı olduğu için her malzemesi ayrılarak özenli bir şekilde tek tek temizliği yapılır. Bazı yerlerinin özel makinesi vardır ve oralara makine ile temizlemek gerekir. Turbonun temizlik gibi kurulaması da çok önemlidir. Kurtulmasına da büyük bir özen gösterilerek iyi bir şekilde yapılmalı. Bu temizlik ve turbo tamiri aracın sahibi tarafından değil, usta bir kişi tarafından yapılması çok önemlidir. Çünkü aracın sahibi bu aşamalarda yıkıma da sebep olabileceği unutulmamalıdır.

german version of the Timb to Climb (for aircraft) presentation by Paul Lamar

14 pages

german keywords: Wankelmotor / Kreiskolbenmotor
English Keywords: Wankel Engine / Wankel Rotary Engine / Rotary Piston Engine / Rotary Combustion Engine

Turbo, her türlü araç tipi ve modelinin verimini artmasını sağlayan, yakıt performansını azaltan ve aracın gücü olan bir tür ekipman olarak adlandırılmaktadır. Araçlarda turbo yakıt ve hava karışımını sıkıştırılmasıyla yönlendirilmesi sağlanmaktadır. Bu şekilde aracın daha verimli çalışmasına katkı sağlamış olmaktadır.

Turbochargers are progressively used in modern automotive engines to enhance engine performance and reduce energy loss and adverse emissions. Use of turbochargers along with other modern technologies has enabled development of significantly downsized internal combustion engines. However, turbochargers are major sources of acoustic emissions in modern automobiles. Their acoustics has a distinctive signature, originating from fluid-structure interactions. The bearing systems of turbochargers also constitute an important noise source. In this case, the acoustic emissions can mainly be attributed to hydrodynamic pressure fluctuations of the lubricant film. The developed analytical model determines the lubricant pressure distribution in the floating journal bearings used mainly in the modern turbocharges. This allows for an estimation of acoustic emissions. The use of such an analytical approach is computationally efficient when compared with full numerical analysis approaches, whilst also providing reliable predictions. The results from the developed analytical model are used to determine the power loss as well as sound pressure levels generated in the turbocharger bearings due to oil flow which can be correlated with the acoustic emissions of turbochargers.