Browse Topic: Pipes and ducts

Items (1,229)
The goal of this work is to increase the accuracy and efficiency of hose cutting operations in small scale industries is by designing and building an automatic hose-cutting equipment. The device uses a computer-controlled system to autonomously cut pipes of various sizes and lengths. By means of a stepper motor-driven, rapidly spinning blade, the cutting process is accomplished. Additionally, the machine has sensors that measure the hose's length and modify the cutting position as necessary. Premium components and materials are used in the machine's construction; these are chosen for their performance and longevity. The device is able to boost cut precision and raise industry production all around from 100% to 190% efficient system thereby decreasing labor and time needed for hose cutting operations
Feroz Ali, L.Manikandan, R.Madhankumar, S.Sri Hari, P.Suriya Prakash, T.Vishnu Doss, G.
Linear dynamics simulations are performed on engine components to ensure structural integrity under dynamic loading. The finite element model of the engine assembly must be prepared accurately to avoid under or over design of the engine components. Flexible hoses are present at pipe routings and modeling them in simulations is a challenge because the stiffness of the composite is not known. The hose under study in this paper is a rubber composite with a knitted reinforcement layer. A multiscale modelling approach is presented to characterize the hose stiffness. A representative volume element geometry i.e., unit cell representation of the composite, consisting of the knitted yarn and surrounding rubber is used to establish orthotropic elastic properties at microscale, by performing finite element homogenization using the ANSYS material designer module. The homogenized properties are assigned to the macroscale hose geometry to perform modal analysis simulation in free-free and fixed
Ashodiya, Jay VirendraJayachandran, JanarthananSanthosh, B
ABSTRACT Current standard military vehicle thermal management systems are based on single phase air/liquid cooling. To meet increasingly stringent demands for high power electronics thermal control, two-phase cooling solutions show great potential and can satisfy the need for compact and high heat flux heat acquisition, transport and dissipation under vibration and shock conditions. One novel two-phase cooling technology that has been developed in this work is a new Heat Pipe Loop (HPL), which exploits the advantages of both heat pipes and loop heat pipes while eliminating their shortcomings. Similar to heat pipes and loop heat pipes, the HPL operates on evaporation and condensation of a working fluid and uses capillary forces in the wick for the fluid circulation. Unlike in a heat pipe, the liquid and vapor in the HPL flow in separate passages made from smooth wall tubing. This results in a low pressure drop and consequently great heat transfer capacity and distance over which the
Tang, XudongZuo, JonGoryca, Mary
In the context of Battery Electric Vehicles (BEVs), airborne noise from Heating, Ventilation and Air Conditioning (HVAC) ducts becomes a prominent concern in the view of passenger comfort. The automotive industry traditionally leverages Computational Fluid Dynamic (CFD) simulation to refine HVAC duct design and physical testing to validate acoustic performance. Optimization of the duct geometry using CFD simulation is a time-consuming process as various design configurations of the duct have to be studied for best acoustic performance. To address this issue effectively, the proposed a novel methodology uses Gaussian Process Regression (GPR) to minimize duct noise. Present solution demonstrates the power of machine learning (ML) algorithms in selecting the optimal duct configuration to minimize noise. Utilizing both real test data and CFD results, GPR achieves remarkable accuracy in design validation, especially for HVAC air ducts. The adoption of GPR-based ML algorithms significantly
Althi, Tirupathi RaoManuel, NaveenK, Manu
Airflow directionality in a vehicle cabin is one of the concerns of car owners, researchers, and vehicle manufacturers. After exposed/parked in hot ambient condition for a long time, HVAC system normally takes few minutes to cool down and reach an acceptable cabin temperature for the passenger comfort. To ensure proper airflow distribution inside the cabin, the AC duct & vanes ability to direct airflow must be evaluated. Objective of this work is to propose a methodology for developing the vane design of AC system duct using CFD approach. Two different goals are attempted. Firstly, the effect of horizontal and vertical vane angle on airflow directionality is investigated with DoE approach. Then factors influencing the airflow directionality are investigated using factorial study approach. CFD based factorial analysis (L9 orthogonal array) was conducted using three components at three levels. The impact of number of horizontal vanes, number of vertical vanes and distance between them on
Mahesh, ABaskar, SubramaniyanRaju, KumarGopinathan, Nagarajan
Vehicle HVAC noise performance is an important vehicle design validation criterion since it significantly links the brand image of a vehicle. It affects the customer’s buying decision and the business of selling vehicles because it directly affects driving comfort. Customers expect continuous improvement in HVAC noise without compromising cooling performance. The process of cascading vehicle-level acoustic performance to subsystem and component levels becomes an important factor in the vehicle NVH development process. It was found that the component-level [HVAC unit without duct] performance of an HVAC system measured in an anechoic chamber was at par when compared to targets, whereas the subsystem-level performance [HVAC unit with duct and dashboard] was on the higher side of the targets. Advanced NVH tools were used to identify the source of noise at the subsystem level. It helped to locate the source and its transfer path. A design modification done at the transfer path location
Titave, Uttam VasantKalsule, ShrikantNaidu, Sudhakara
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water
M, Amala RajeshSonkar, SurabhiKumar, Mukesh
Bimetal composite pipe has higher strength and is more corrosion and high temperature resistant compared to single metal pipe, making it a new type of pipe that is being gradually applied to important industrial fields such as aviation and aerospace manufacturing. To study the hydraulic forming mechanism of bimetal composite pipes, the forming process is divided into three stages: liner pipe elastic–plastic deformation, base pipe loading, and unloading. The stress and strain relation between the liner and base pipe during the gradual increase in hydraulic pressure is analyzed, and the range of selected internal pressure required for composite pipe formation and the relation between residual contact pressure and internal pressure for the liner–base pipe interface are obtained. The accuracy of analytical predictions for the contact pressure and the axial and circumferential strains on the outer wall of the base pipe during the forming process is verified through numerical simulation and
Tang, Yue
Imagine grasping a heavy object, like a pipe wrench, with one hand. You would likely grab the wrench using your entire fingers, not just your fingertips. Sensory receptors in your skin, which run along the entire length of each finger, would send information to your brain about the tool you are grasping
Attaining better acoustic performance and back-pressure is a continuous research area in the design and development of passenger vehicle exhaust system. Design parameters such as tail pipe, resonator, internal pipes and baffles, muffler dimensions, number of flow reversals, perforated holes size and number etc. govern the muffler design. However, the analysis on the flow directivity from tail pipe is limited. A case study is demonstrated in this work on the development of automotive muffler with due consideration of back pressure and flow directivity from tail pipe. CFD methodology is engaged to evaluate the back pressure of different muffler configurations. The experimental and numerical results of backpressure have been validated. The numerical results are in close agreement with experimental results. It was observed that the influence on back pressure with reducing the quantity of baffle plate, Increasing the tail pipe diameter and twin tail pipe with bypassing flow through inner
Baskar, SubramaniyanLingala, VivekRaju, Kumar
Fuel-efficient motorcycles are essential for energy conservation and environmental load reduction. To achieve low fuel consumption, reducing the weight of the body parts of the motorcycle is important. This study focuses on reducing the weight of the swingarms, a relatively heavy body part. However, reducing the weight of swingarms is challenging owing to the low flexibility in their shape because swingarms are conventionally made of multiple pipes and casting parts welded together. Therefore, we utilized the integral casting technology and examined a new light weight shape. However, creating a new shape manually is difficult. Thus, we examined a new shape using the shape optimization technology, which has been recently used in additive manufacturing. The shapes fabricated using this technology are generally complex and difficult to manufacture by casting. Therefore, we adjusted optimization condition with casting. We derived a new shape which can not only be casted but also has good
Yamamoto, KodaiIto, TakafumiWatanabe, KentaroHosokawa, ShoheiNagasaka, KazuyaEndo, YudaiYoshihiro, MasudaImamura, YusukeMaeda, Fujio
Post-oxidation has been used to enhance the chemical reactions in the exhaust gas pipes, leading to the activations of the turbocharger and catalyst at cold state. In this research, a detailed study of the various mechanisms for post-oxidation is performed. For the post-oxidation activation, the unburned gas species (CO, THC, H2) in the exhaust manifold must be produced by some methodologies, such as scavenging, lambda-split, and post-injection. The required amount of O2 concentration can be either supplied by the scavenging (valve overlap tuning) or the secondary air injection (SAI) system. Mixing the species is also an important key to promoting post- oxidation, and an internal bypass adapter with a modified exhaust adapter shape was developed and evaluated
Ishikawa, TeruakiKumar*, MadanMoriyoshi, YasuoKuboyama, Tatsuya
This study was visualized by experimental and numerical analysis for the unknown injected droplet phenomena with the multi-phase flow in the Urea-SCR dosing system. Visualization experiments were conducted on the droplet behavior inside the pipe with simulated urea SCR injection system. Although the total number of droplets decreases at gas temperatures of 150°C and 200°C, a significant number of injected droplets remained at the position corresponding to the SCR catalyst. That is physical kinetic energy was found to dominate over thermal evaporation. However, the impingement of droplets into the pipe wall had occurred complex behavior by physical/thermal evaporation, and these droplets weren't on gas airflow at the lower part of the pipe. Furthermore, these actual phenomena were reflected in experimental coefficients for new reduction model analysis instead of CFD
NOHARA, TetsuoSUGIYAMA, NaokiNARA, ShotaroONO, JyoONOUE, HirokiOSADA, RinaKAWAMOTO, YukiOCHIAI, MasayukiTAKAHASHI, ShunOOSUMI, KazuoISHIKAWA, Naoya
In the modern era of automotive industry, occupant comfort inside the cabin is a basic need and no more a luxury feature. With increase in number of vehicles, the expectations from customers are also changing. One of the major expectations from real world customers is quick cabin cooling thru all seasons, particularly when the vehicle is hot soaked and being used in summer conditions. Occupant thermal comfort inside the vehicle cabin is provisioned by a mobile air conditioning (MAC) system, which operates on a vapor compression-based cycle using a refrigerant. The main components of a direct expansion (DX) based MAC system are, a compressor, condenser, evaporator, and expansion valve. Conditioned air is circulated inside the cabin using a blower, duct system and air vents. The AC condenser is the most critical component in AC circuit as it rejects heat, thereby providing for a cooling effect inside the cabin. Right sizing and packaging of condenser, optimizing the condenser core
Shukla, Ankit KumarTadigadapa, SureshDimble, Nilesh
AC system provides the human comfort inside the cabin of a vehicle but at the expense of consumption of energy from the vehicle. On a global perspective for the bus segment, there is an increased demand for cooling in tropical countries. Optimization needs to be done in existing AC systems w.r.t packaging, cost & performance constraints. Major elements contributing to heat ingress are engine hood, front firewall, windshield & side glasses and bus body parts. Due to these reasons inadequate passenger comfort and poor cool down performance of the vehicle is observed. This paper refers to the reduction of heat ingress through different DOE (Design of Experiment) in the area of design & validation for duct & vent layout, insulation, glass & paint technology, evaporator blowers. The new duct design has been evaluated using a CFD tool by varying various parameters to generate desired output. The integrated use of the modifications was found significant improvement at vehicle level
Dodwad, AbhishekNagarhalli, Prasanna VFartade, SunilAhire, Uttam Namdeo
As HVAC noise is becoming one of the key factors to end users in terms of enhanced comfort, it is important to understand and evaluate various noise sources of HVAC in details. With detailed understanding of various sources, it becomes easier to take appropriate countermeasures in design and subsequently eliminate. There are many methods available in industry to investigate the noise sources in details however those options are expensive and time consuming and require deep understanding of the acoustic. Acoustical duct methods are one such method which proves to be very much helpful in identifying the noise sources from different aggregates like kinematics mechanism, door/damper, servomotors, heat exchangers etc. These sources are typically defined minor noise sources. The present paper describes the detailed investigation of those minor noise sources through the use of acoustical duct method. An existing HVAC from passenger car was considered for this study. In order to take the noise
Sen, SomnathGoel, Arunkumar
As the automotive industry is transitioning from conventional engine driven to electric battery driven, many of the vehicle aggregates are getting re-engineered and changing accordingly. Being air-conditioning manufacturer one of the aggregates that needs attention and focused effort is the Heating Ventilation and Air Conditioning system (HVAC). Acoustic comfort of electric vehicle gets impacted due to the HVAC noise in absence of engine and hence other noise sources becomes prominent which were earlier masked by the engine noise. It is important to understand the HVAC noise sources for implementing right countermeasures for masking the noise. There are three methods of noise source identification namely acoustical duct method, cocooning or lead covering method and near field method. Out of these method, acoustical duct method and near field methods are used for minor and major noise identification in this study. The present paper describes the comparative study of HVAC noise source
Goel, ArunkumarSen, Somnath
Computational icing analysis results were compared to experimental icing tunnel data including aerothermal (e.g., dry air) and supercooled water droplet rime-ice conditions from tests conducted in early 2022 at the NASA Icing Research Tunnel (IRT). The Simulated Inter-compressor Duct Research Model (SIDRM) test article was used in this study, and its geometry represents the inter-compressor duct region of a turbofan engine. The test article’s purpose is to study the physics of supercooled water icing and ice crystal icing. This study compared three different icing codes: FENSAP-ICE (Eulerian approach), LEWICE3D (Lagrangian approach), and GlennICE (Lagrangian approach). All three icing codes were conducted on SIDRM’s complex body flow-field and compared to different experimental supercooled water rime runs. The test article instrumentation (pressure taps, thermocouples, etc.) and 3D laser scans of final ice shapes were used to compare against the different icing code simulations. The
Stewart, EricBartkus, Tadas
Considerable amounts of water accumulate in aircraft fuel tanks due to condensation of vapor during flight or directly during fueling with contaminated kerosene. This can result in a misreading of the fuel meters. In certain aircraft types, ice blocks resulting from the low temperatures at high altitude flights or in winter time can even interfere with the nozzles of the fuel supply pipes from the tanks to the engines. Therefore, as part of the maintenance operations, water has to be drained in certain intervals ensuring that no remaining ice is present. In the absence of an established method for determining residual ice blocks inside, the aircraft operator has to wait long enough, in some cases too long, to start the draining procedure, leading potentially to an unnecessary long ground time. A promising technology to determine melting ice uses acoustic signals generated and emitted during ice melting. With acoustic emissions, mainly situated in the ultrasonic frequency range, a very
Pfeiffer, HelgeReynaert, JohanSeveno, DavidJordaens, Pieter-JanCeyhan, OzlemWevers, Martine
This paper is focused on the numerical analysis of the impingement and water catch rate of snow particles on the engine air intake of the Next Generation Civil Tilt Rotor (NGCTR). This NGCTR is developed by Leonardo Helicopters. The collection efficiency and water catch rate for the intake geometry are obtained for the test cases that have been defined for the relevant snow conditions. These conditions are related to the flight envelope of the NGCTR, existing EASA/FAA certification specifications, and the snow characterization. The analyses have been performed for the baseline air intake geometry. A range of particle diameters has been simulated with a particle density equal to the density of ice and with a particle drag relation that disregards the particle shape. Based on the results for the water catch rate on the basic nacelle configuration in snow conditions it is concluded that the ‘cheeks’ of the duct are more susceptible to impingement of larger snow crystals (>75 μm), whereas
Kool, NinaVan der Weide, EdwinSpek, Ferdinandvan der Ven, Harmenvan 't Hoff, Stefan
This paper focuses on the design of the thermoelectric ice protection system (IPS) for the engine air intake of the Next Generation Civil Tiltrotor (NGCTR), a demonstrator under development in Leonardo Helicopters. A specific IPS design strategy for the novel intake configuration is proposed. The main constraint which driven the design strategy is a maximum power of 10.6 kW available for the full intake IPS system. The IPS was designed for safe aircraft operations within the Appendix-C icing envelope. The numerical approach adopted to perform the design and the resulting IPS concept are presented. Calculations of the required IPS heat fluxes revealed that maintaining running wet conditions on the entire intake surface is not feasible due to the limitation to the maximum IPS power demand. Therefore, a de-icing IPS design strategy is proposed. The anti-icing mode is adopted only on the lip region to avoid formation of ice caps whereas de-icing zones are defined within the intake duct
Tormen, DamianoZanon, AlessandroDe Gennaro, Michele
In-flight icing is an important safety issue and is a factor that affects aircraft design and performance. Newer regulations are driving a need for improvements in airframe and engine icing simulation capability. Experimental data is required for development of icing physics models and simulation validation. To that end, this paper presents the analysis of the supercooled liquid icing data subset from tests conducted in 2022 at the NASA Icing Research Tunnel that studied both supercooled water and ice-crystal icing. The test article that was utilized replicated 3D geometrical features of an inter-compressor duct and strut region of a turbofan engine. The surfaces of the Simulated Inter-compressor Duct Research Model (SIDRM) can be heated to simulate the warm surfaces of the turbofan inter-compressor duct. The test article is instrumented with pressure taps, heaters, heat flux gauges, and thermocouples, while a 3D laser scanner, cameras, and a scale to measure ice mass were utilized to
Bartkus, TadasLee, SamStewart, Eric
Automotive Heating Ventilation and Air Conditioning (HVAC) system is essential in providing the thermal comfort to the cabin occupants. The HVAC noise which is typically not the main noise source in IC engine vehicles, is considered to be one of the dominant sources inside the electric vehicle cabin. As air is delivered through ducts and registers into the cabin, it will create an air-rush/broadband noise and in addition to that, any sharp edges or gaps in flow path can generate monotone/tonal noise. Noise emanating from the HVAC system can be reduced by optimizing the airflow path using virtual tools during the development stage. This paper mainly focuses on predicting the noise from the HVAC ducts and registers. In this study, noise simulations were carried-out with ducts and registers. A Finite Volume Method (FVM) based 3-dimensional (3D) Computational Fluid Dynamics (CFD) solver was used for flow as well as acoustic simulations. Large Eddy Simulation (LES) was used for flow field
George, Binoj K.Garikipati, NagababuDoroudian, MarkHorne, KevinVoonna, KiranErbig, Lars
Automobile exhaust systems help to attenuate the engine combustion noise as well as the high frequency flow noises which are generated as the gas expands and contracts through various ducts and orifices of muffler system. One of the solutions to mitigate the noise generated due to the latter is by means of an absorptive muffler, comprising a fibrous acoustic medium which helps to absorb noise of certain frequencies which are sensitive to the human ear. Typically, the construction of such a system consists of the fibrous acoustic medium encompassing a perforated inner pipe on the inside and enclosed by an outer metal case on the outside. The temperature limitations of the acoustic medium sometimes necessitate the placement of the fibrous acoustic system away from the engine source in order to prevent any damage to the fibers upon direct contact with the flue gas. However, this results in a potential for condensation of engine out gas in and around the inner pipe – fibrous system
Vineeth, S.Mishra, ManishTripathi, Manas
The acoustic muffler is one of the practical solutions to reduce the noise in ducts. The acoustic and aerodynamic performances are two critical indices of one muffler for the air intake system of a hydrogen fuel cell electric vehicle (FCEV). In this study, the concept of phononic crystal is applied to design the muffler to obtain superior acoustic performance. One duct with periodic and compact resonator-type mufflers is designed for broadband noise attenuation. The two-dimensional (2D) transfer matrix method and bandgap theory are employed to calculate the transmission loss (TL) and acoustic bandgap. It is numerically and theoretically demonstrated that broadband noise attenuation could be acquired from 500Hz to 3500Hz. Afterwards, the three-dimensional (3D) computational fluid dynamics (CFD) approach is applied to predict the pressure distribution. The results indicate that the proposed hybrid muffler and the phononic crystal duct possess low pressure loss values. Furthermore, the
Liu, PanxueZuo, ShuguangWu, XudongYin, BinLi, Shanran
Good heat dissipation of Lithium battery can prevent the battery from shortening its life due to rapid aging or thermal runaway. In this paper, an air-cooled structure of 5 series and 3 parallel battery packs is designed, which combines the advantages of series and parallel air ducts and optimizes the heat dissipation effect and the space ratio of air ducts. First, the heat generation model of NCR18650PF lithium battery is established, and the heat generation rate and time under different discharge rates are calculated. Combined with the working conditions of the battery itself, the necessity of battery pack heat dissipation was found. Secondly, a preliminary three-dimensional model of the battery pack heat dissipation was established, and a simulation analysis was carried out to study the influence of the inclination angle of the inlet duct, the arrangement of the air inlet and outlet, and the influence of the deflector on the heat dissipation effect, and the optimization analysis was
Ding, KangjieLin, ZhenmaoXie, Beichen
A new technique enables the detection of SARS-CoV-2, the virus that causes COVID-19, in the air by using a nanotechnology-packed bubble that spills its chemical contents like a broken piñata when encountering the virus. Such a detector could be positioned on a wall or ceiling, or in an air duct, where there’s constant air movement, to alert occupants immediately when even a trace level of the virus is present
Compression ignition engines are widely used in the cargo and passenger transport sectors, this is due to their high energy efficiency and can operate with renewable fuels. The search for increased efficiency in internal combustion engines and reduced emissions are increasingly stringent, so to meet regulatory emission standards, new technologies are being studied and developed to reduce emissions generated by engines, in the case of diesel engines compression ignition, studies of techniques to reduce NOx and soot have been carried out. One of the techniques studied is the application of the DFI - Ducted Fuel Injection concept, which makes the fuel spray pass through a small cylindrical duct installed upstream of the injection orifice of the injector nozzle, thus improving the air/fuel, making it more homogeneous and allowing a more complete combustion. This work addresses a study of this application of DFI with different compression ratios. To carry out the tests, a thermodynamic
Jairo Dias, FábioLacava, Pedro TeixeiraRufino, CaioCastejon Garcia, EzioLomonaco, Raphael
Vehicles wind shield are designed to provide a clear visibility in winter as its one of the most important requirement for the comfortable and safe journey. In extreme winters, wind shield of vehicle is covered with layer of ice and if frosted happened, results in reduces the visibility distance. To increase the visibility and providing the comfort to driving the vehicle, heater is used in vehicle as an integrated part of vehicle HVAC System. When the blower air passes through heater, air temperature gets increased. When the hot air is injected through grill at designed angle of injection and at selected air velocity on wind shield surface, ice on wind shield melting due to convection heat transfer phenomenon and thus achieved a clear windshield glass and clear visibility at driver and at co-driver area. The Objective of this paper is to optimize the design of Vehicle DUCT to improve the visibility within required timeline at driver and co-driver area under required environment
Meena, Avadhesh KumarKushwah, ManvendraSingh, Shobit KumarKishore, KamalSen, Somnath
Heating, ventilation and air conditioning systems play a crucial role in our day-to-day activities. With rise in global warming, leading to climate change, HVAC unit is the need of the hour. With average temperatures on the rise, it is quite imperative that the unit provides better thermal comfort to the passengers. Off-road vehicles like tractor, is also no exclusion. Tractor drivers have to experience adverse weather conditions out in the open field. Thus it is quite fundamental that sufficient airflow reaches every point inside the driver cabin, ensuring proper cool-down. To ensure proper distribution of airflow inside the cabin, optimization of HVAC unit needs to be properly carried out. The present study shows how an HVAC of an off-road vehicle is properly optimized with the help of Computational Fluid Dynamics. STAR-CCM+ v2021.2.1 is used as solver for the simulation. Airflow simulation of inside cabin is also carried out in both initial and optimized design and cooldown
Singh, Shobit KumarSen, SomnathGoel, ArunkumarParayil, PaulsonBaruah, Murchana
As the current market trend is emerging towards the compactness, better comfort and less emission, it is quite important that factors contributing to these aspects should be kept under control and maintained within the desired range. Heating ventilation and air conditioning (HVAC) noise is one such factor which significantly contributes in occupants’ acoustic comfort. It creates discomfort to the occupants while HVAC is in operation and eventually lead to fatigue. In a HVAC, there are several different types and sources of noise which cumulatively impacts the overall noise level. However, few of them are quite prominent and has maximum impacts on overall noise. It is very important to identify and measure these sources in order to take appropriate countermeasure to mask or eliminate them. In order to identify and measure the noise sources, various methods are used. One such method is acoustical duct method in which an acoustic duct is used to isolate the source for measuring the noise
Goel, ArunkumarSen, Somnath
Under the emerging urban air mobility (UAM) concept, electric vertical take-off and landing (eVTOL) aircraft were designed to alleviate urban traffic congestion due to their advantages of low take-off and landing site requirements, less pollution, low noise, and strong stability. However, due to the high-level power consumption of eVTOL and only having air flight mode, this kind of aircraft has a severe shortage of cruising range. To improve the endurance and dynamic performance, the flying car designed in this paper added a ground driving mode based on eVTOL and used distributed ducted fans to provide lift. And the influence of different power transmission routes on the dynamic and economic performance of the flying car was analyzed. On this basis, the overall take-off weight of the flying car was estimated through an iterative algorithm, and parameter design and power system matching for each part of the components were conducted. Finally, this paper used MATLAB/Simulink to build a
Shao, YifanLiu, LiangXu, Zhaoping
Presently, the automotive industry is being renovated with the help of an electrical machine, batteries, and power electronic components. In this technological shift, permanent magnet machines (PMSM) are mainly preferred for traction, because of their high efficiency and power density. The noise, vibration, and harshness (NVH) performance of the electrical machine is one of the main challenges, due to the tangential and radial electromagnetic forces. In this research study, a geometrical and electrical approach has been executed to reduce the radial force, which has a larger impact on vibration and noise. Initially, a permanent magnet synchronous motor with a V-shaped magnet configuration has been designed and the output performances are analyzed. The base structure (V-shaped magnet without duct) highlights that the radial force in the 12/3 and 12/12 order is higher, which will increase the vibration and noise of the motor. In this proposed geometrical approach, a duct has been
Kondaveeti, YedukondaluGanesan, Aswin uvarajPanchada, Jagadish
In modern conditions, the rising cost of fuel and the adoption of more stringent environmental standards in developed countries require a reduction in fuel consumption by vehicles. The profitability of the trucking industry depends on the fuel economy of trucks, which, in turn, is determined by many factors, including their aerodynamic characteristics. The article substantiates new ways of reducing the aerodynamic drag of road trains based on a study conducted by the authors. Numerical simulation of the road train aerodynamics allows us to determine the distribution of velocity, pressure, and air turbulence zone around it. The effectiveness of known and proposed technical solutions to reduce the aerodynamic drag of trains with the use of spoilers of various designs has been evaluated and implemented. An effective way to reduce the aerodynamic resistance of road trains is proposed. The method is to use air ducts as a part of the semi-trailer through which air flows in from the front and
Gritsuk, Igor ValeriyovichBatrachenko, OleksandrTarandushka, LiudmylaMitienkova, ViraBazhinov, OleksiyBazhynova, Tetiana
A rapid publicity growth has led to an extensive application of micro-perforated (MP) acoustic elements for broadband sound absorption in the exhaust systems of the internal combustion engine. Most typically, the MPs are exposed to grazing flow conditions, studied thoroughly by various authors in the past decades and represented by adequate acoustic models by now. However, in certain exhaust system designs implemented in the fibreless silencers of modern ground vehicles, an alternative layout for the tubular flow duct MP elements - the flow plug condition has been proven to be useful. In this type of MP’s application, the propagating gas flow is entirely guided through the micro-perforated sections upstream and downstream of the rigid plug, typically increasing the flow resistivity and the viscous damping of the sound in duct. Acoustic studies on such type of MP’s operating condition are scarce. This paper focuses on the noise control properties of a silencer incorporating tubular MP
Villau, MargusRämmal, HansLavrentjev, Jüri
Recently, an aerodynamic theory for active grille shutters (AGS) of road vehicles has been developed that analytically describes the relationship among the flap position, cooling air mass flow, and drag. The experimentally validated theory is based on the assumption of a geometrically simple shutter which is arranged in a straight air duct and is flowed frontally, i.e., perpendicular to the flap plane. In the present work, this theory is extended and it is investigated how an inclined position affects the aerodynamic characteristic of an AGS. The theoretical results are then validated experimentally. Measurements on real vehicles with suitable AGS are used for this purpose. The results show good agreement between the theoretical predictions and experiment. The theoretical and experimental analyses allow conclusions to be drawn about how and under what conditions an inclined position affects the aerodynamic behavior of AGS
Wolf, Thomas
The feasibility of a recently developed eddy-resolving model of turbulence, termed as Very LES (Large-Eddy-Simulation), was tested by simulating the flow dynamics in two moving piston-cylinder assemblies. The first configuration deals with the compression of a tumbling vortex generated during the intake process within a cylinder with the square cross-sectional area, for which the reference experimental database was made available by Borée et al. (2002). The second piston-cylinder assembly represents a realistic motored IC-Engine (Internal-Combustion Engine) with the multiple Y-shaped intake and outtake ducts in which the movable valves are accommodated. The boundary and operating conditions correspond to the experimental study performed by Baum et al. (2014). The VLES simulation model applied presently is a seamless eddy-resolving hybrid RANS/LES (Reynolds-Averaged Navier-Stokes / Large-eddy Simulation) model. As the RANS constituent of this modelling scheme an appropriately sensitized
Chang, Chi-YaoKrumbein, BenjaminBopp, MaximilianBasara, BranislavSadiki, AmsiniHasse, ChristianDreizler, AndreasBoehm, BenjaminJakirlic, Suad
The emergence of additive manufacturing (AM) technology has enabled the internal cooling channel layout for high pressure aluminium die casting (HPADC) tools to be designed and modified without topological constraint. Optimisation studies of a full industrial HPADC mould for extending the tool service life has received limited attention due to the high geometrical complexity and the various physics with multi time- and length- scales in addition to the manufacturability limitations. In this work, a new computationally efficient algorithm that employs the adjoint optimisation method has been developed to optimise the coolant channels layout in a complete mould with various 3D printed inserts. The algorithms significantly reduced the computational time and resources by decoupling the fluid flow in the coolant channels from the tool and simulating them separately. The channel’s heat transfer coefficient values are then interpolated and mapped into the thermal model that implements the
Zeng, TongyanAbo-Serie, Essam F.Jewkes, JamesDodd, PaulJones, Rhys
Designing an efficient vehicle coolant system depends on meeting target coolant flow rate to different components with minimum energy consumption by coolant pump. The flow resistance across different components and hoses dictates the flow supplied to that branch which can affect the effectiveness of the coolant system. Hydraulic tests are conducted to understand the system design for component flow delivery and pressure drops and assess necessary changes to better distribute the coolant flow from the pump. The current study highlights the ability of a complete 3D Computational Fluid Dynamics (CFD) simulation to effectively mimic a hydraulic test. The coolant circuit modeled in this simulation consists of an engine water-jacket, a thermostat valve, bypass valve, a coolant pump, a radiator, and flow path to certain auxiliary components like turbo charger, rear transmission oil cooler etc. A commercial CFD software, Simerics-MP+®, is used to simulate the hydraulic test for two different
Ballani, AbhishekBhagat, MeghrajSrinivasan, ChiranthPasunurthi, ShyamSundarMaiti, DipakZhang, YiMotin, Abdul
Ducted Fuel Injection (DFI) is a new technology recently developed with the aim of reducing soot emission formation in diesel compression ignition engines. DFI concept consists of the injection of fuel spray through a small duct located downstream of the injector nozzle leaving a certain gap, the so-called Stand-off distance. Currently, CFD modelers have investigated its performance using classical spray modeling techniques such as the Discrete Drops Method (DDM). However, as discussed in the literature, this type of technique is inappropriate when applied to dense jets as those occurring in diesel sprays, especially in the near-nozzle region (where the duct is placed). Therefore, considering a more appropriate modeling technique for such a problem is mandatory. In this research work, an Eulerian single-fluid diffuse-interface model called Σ-Y and implemented in the OpenFOAM framework is utilized for the simulation of non-reacting conditions. The model relevance is twofold, as it is
Pandal, AdrianRahantamialisoa, FanirySahranavardfard, NasrinPostrioti, LucioBattistoni, Michele
Ducted fuel injection (DFI), a concept that utilizes fuel injection through ducts, was implemented in a constant pressure High Temperature Pressure Vessel at 60 bar ambient pressure, 800-1000 K ambient temperature, and 21 % oxygen. The ducts were 14 mm long and placed 3-4.7 mm from the orifice exit. The duct diameters ranged from 1.6-3.2 mm and had a rounded inlet and a tapered outlet. Diesel fuel was used in single-orifice fuel injectors operating at 250 MPa rail pressure. The objective of this work was to study soot reduction for various combinations of orifice and duct diameters. A complete data set was taken using the 150 μm orifice. A smaller data set was acquired for a 219 μm orifice, showing similar trends. Soot reduction peaked at an optimal duct diameter of 2-2.25 mm, corresponding to an 85-90 % spray area reduction for the 150 μm orifice. Smaller or larger duct diameters were less effective. Duct diameter had a minimal effect on ignition delay. Ambient temperature had an
Svensson, KenthFitzgerald, RussellMartin, Glen
Idle sound quality for motorcycles is very important to the customers [1,2]. People would like to have a strong individualized sound in idle, linear and smooth sound in the driving condition. Since the idle fluctuation noise is based on the engine firing sequence, the exhaust manifold structure and the idle frequency eight or six cylinders engine are really hard to get a real good fluctuated tailpipe sound in the idle condition compared to the two or three cylinders engines. However, some surrogate methodology can be applied to these engines. Based on the noise cancellation process in amplitude and phase in the exhaust manifold system, engineers can manipulate the noise with several lower peaks, and the other higher peaks can be perceived by the masking effect in the time domain. In this scenario, people only feel the big noise fluctuation peaks, even the smaller peaks are still there in the background. In addition, waves can be further improved by the Hot-End structure. The structure
Tan, Yang
Ducted Fuel Injection (DFI) has the potential to reduce soot emissions in Diesel engines thanks to the enhanced mixing rate resulting from the liquid fuel flow through a small cylindrical pipe located at a certain distance from the nozzle injector hole. A consolidated set of experiments in constant-volume vessel and engine allowed to understand the effects of ambient conditions, duct geometry and shape on fuel-air mixing, combustion and soot formation. However, implementation of this promising technology in compression-ignition engines requires predictive numerical models that can properly support the design of combustion systems in a wide range of operating conditions. This work presents a computational methodology to predict fuel-air mixing and combustion with ducted fuel injection. Attention is mainly focused on turbulence and combustion modelling. The first is mainly responsible for the mixture formation process in presence of large velocity gradients and flow recirculations, while
Lucchini, TommasoZhou, QiyanD'Errico, GianlucaSevergnini, Davide
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