Browse Topic: Valves

Items (2,967)
ABSTRACT Based on the foundation of thermal management system developed by Rocky Research and working closely with TARDEC personnel, this paper addresses design, development, and testing of two delivered environmental control prototypes to TARDEC. The delivered prototypes are electrically driven vapor compression systems enhanced with Rocky Research vector drive for speed control, use of Pulsing Thermal Expansion Valve (PTXV) for precise refrigerant control, and power electronic package capable of running efficiently from both AC and DC power sources seamlessly. These prototypes were fully tested at different ambient temperature conditions at Rocky Research environmental chamber and their performance were logged and documented. The cooling capacity was measured to be in range of 6,000 to 12,000 Btu/hr and the Coefficient of Performance (COP) was measured to be above 1.5 at high ambient temperature conditions. This reflects close to 50% improvement in efficiency, when compared to
Khalili, KavehSpangler, ChrisSchultz, Andrew
With the advent of electric and hybrid drivetrain in the commercial vehicle industry, electrically driven reciprocating compressors have gained widespread prominence. This compressor provides compressed air for key vehicle systems such as brakes, suspension systems and other auxiliary applications. To be a market leader, such an E-compressor needs to meet a myriad of design requirements. This includes meeting the performance by supplying air at required pressure and flow rate, durability requirements and having a compact design while maintaining cost competitiveness. The reed valve in such a compressor is a vital component, whose design is critical to meet the aforementioned requirements. The reed valves design has several key parameters such as the stiffness, natural frequency, equivalent mass, and lift distance which must be optimized. This reed valve also needs to open and close rapidly in response to the compressor operating speed. Since it is the order of milliseconds, the valve
J, BharadwajT, SukumarPendyala, Vamsi KrishnaPaul Pandian, Adheenthran
This standard covers oxygen masks and breathing valves used with both panel mounted and mask mounted demand and pressure-demand oxygen regulators. Mask mounted oxygen regulators are covered under other standards, but when the mask mounted regulator incorporates an integral exhalation valve, the performance of this valve shall meet the requirements of this standard
A-10 Aircraft Oxygen Equipment Committee
Sodium is used as a coolant in the fast reactor’s primary and secondary loops to transfer enthalpy from the reactor and transport it to the expander. However, handling sodium is difficult, and it can be hazardous if it comes into contact with air, which causes an exothermic reaction. During maintenance of sodium loop components, isolation is typically accomplished with valves. The valve leaking is caused by the seal or the gland. Seal leakage is compensated because it occurs within the line, but gland leakage should be zero because the liquid is harmful. To address this requirement, the author attempted to design a special type of valve in which sodium is allowed to rise through an annular path along the stem and heat transfer is augmented in such a way that the required enthalpy is evacuated to freeze sodium inside the annular path, confirming the fail-safe zero gland leakage. A finned tube assembly is fitted around the stem to achieve this concept of expanded surface heat transfer
Kudiyarasan, SwamynathanBiswas , Sitangshu Sekhar
The work presented is a comparative analysis between Reynold’s Averaged Navier Stokes (RANS) and Large Eddy simulation (LES) description of turbulence to capture the in-cylinder flow structures. Simulations are performed using RNG k - € RANS model and LES one equation eddy viscosity model with Werner and Wengle wall model. ECFM combustion model has been used to achieve the desired rate of heat release when compared against the experiments. KH-RT spray model has been used to define the primary and secondary breakup of parcels. A Renault engine operating on Miller cycle has been chosen for this study. Consecutive perturbation method (CPM) available in Converge has been used to take the advantage of availability of higher number of cores to reduce the effective CPU time. Results of RANS simulation indicates that increase in valve overlap results in faster tumble decay compared to LES. Moreover, it is also found that LES required lesser tuning of flame stretch due to turbulence and a
V G, SrujanServant, CedricRathinam, Balamurugan
In today’s rapidly evolving automotive world, reduction of time to market has prime importance for a new product development. It is critical to have significant front-loading of the development activities to reduce development time while achieving best in class performance targets. Driver-in-the-loop (DIL) simulators have shown significant potential for achieving it, through real time subjective feedback at preliminary stages of the vehicle development. Recent advances in technology of driving simulators have enabled quite accurate representation steering and handling performance, also good prediction on primary ride and low frequency vibrations. In conventional damper development, the definition of the initial dampers tuning specifications typically requires a mule vehicle, or atleast, a comparable vehicle. However, this approach is associated with protracted iterations that consume substantial time and cost. This becomes even more critical when introducing new damper technology on
Rasal, ShraddheshAsthana, ShivamVellandi, VikramanArconada, Verónica SantosTosolin, Guido
Solid rods of dissimilar metals are easily welded by friction welding. This process is a solid-state process where no fumes or gases are released which is friendly to the environment. In advanced engineering practice, joining Titanium (Ti) alloy and stainless steel (SS) is very important due to poor bonding strength in direct joining. These materials are easily joined by an interlayer technique using materials like nickel, silver, niobium, aluminum, and copper. Special surface geometry techniques hold the interlayer materials between dissimilar metals in different forms like coating, foils, and solid metals. In this investigation, the finite element method is used for modeling the process, and the Johnson-cook equation was used to find the analysis of output values with the defined material properties. The heat generated is calculated and numerically compared and analyzed with experimental results. Observations such as metallography, hardness, and tensile test were studied. The results
Balasubramanian, M.Prathap, P.Madhu, S.
The process of manufacturing high-quality and reliable balloon catheters is critical to a number of advanced medical treatments for patients including balloon angioplasty, stent and drug delivery, transcatheter aortic valve implantation, atherectomy, renal denervation, and laser balloon angioplasty. These minimally invasive procedures have vastly improved quality of life, increased patient safety, decreased recovery times, and lowered treatment costs for patients around the globe
A Proton Exchange Membrane Fuel Cell requires the input of Oxygen from the Cathode and Hydrogen from the anode. As atmospheric air is fed into the system for power generation, nitrogen molecules enter the fuel cell along with oxygen molecules. Over time, an accumulation of nitrogen inside the fuel cell leads to an increase in the effective impedance, which in turn leads to an increase in losses inside the fuel cell, hence reducing the fuel cell efficiency. To reduce the losses, most of the PEM fuel cells have a purge valve at the anode. This purge valve is operated frequently as the impedance increases to let out the nitrogen molecules. During the purging operation, some amount of Hydrogen is let out along with nitrogen, which cannot be recovered. In other words, loss of Hydrogen could also be considered in terms of reduction in system efficiency. Conventionally, nitrogen purging operation in fuel cell takes place reactively as voltage/ power drop across the electrode increases above a
Shah, SaurabhBhat, AdithyaMunirajappa, ChandrashekaraPrasad P, ShilpaChoubey, Ayush
Manufacturers of automation components have long made pneumatic valve terminals with IP65 and IP67 ratings that can be mounted anywhere on a machine. This is particularly useful for connecting valves as close to pneumatic actuators as possible. Doing so shortens the length of tubing, reduces the occurrence and severity of leaks, and increases actuator performance by shortening cycle times. Decentralized valve terminals communicate with the machine controller or PLC via an industrial Ethernet network. In addition to valves, terminals are configured with input and output modules to allow for easy connection of sensors, switches, and other field-level devices to the industrial network
Pneumatic valves are widely used in heavy commercial vehicles’ air braking systems. These valves are mainly used in the braking system layout to maintain the vehicle stability during dynamic conditions. Rubber components are inevitable in valves as a sealing element, and it is very difficult to predict the behavior due to its nonlinear nature. Basically, this valve efficiency is defined in terms of performance and response characteristics. These characteristics are determined in the concept stage itself using 1D simulation software. AMESim software has a variety of elements to use in a unique way for performance and response behavior prediction. For pneumatic valves, 1D analysis is an effective method and it gives good correlation with actual test results. During the modelling of pneumatic valves, some of the contacts between rubber and metals are controlled by various parameters such as damping, contact stiffness and desired phase angle. Instead of giving these parameters to a linear
Kandasamy, SugumarT, SukumarPendyala, Vamsi KrishnaGovindarasu, Anbarasu
Rotary valve technology can provide increased flow area and higher discharge coefficients than conventional poppet valves for internal combustion engines. This increase in intake charging efficiency can improve the power density of four-stroke internal combustion engines, particularly at high engine speeds, where flow is choked through conventional poppet valves. In this work, the valvetrain of a light duty single cylinder spark ignition engine was replaced with a rotary valve train. The impact of this valvetrain conversion on performance and emissions was evaluated by comparing spark timing sweeps with lambda ranging from 0.8 to 1.1 at wide open throttle. The results indicated that the rotary valvetrain increased the amount of air trapped at intake valve closing and resulted in a significantly faster burn duration than the conventional valvetrain. Additionally, the spark to CA10 burn duration of the rotary valvetrain was highly sensitive to spark timing, which was not true of the
Gainey, BrianVaseleniuck, DarrickCordier, DanGarrett, Norman
Scroll compressors are commonly used in HVAC and thermal management systems of electric and hybrid vehicles because of its high operating efficiency and smooth operation. The compressor is driven by an electric motor which forms a coupled system called an e-compressor unit. The refrigerant cools the motor before entering the scroll compressor. At different operating conditions of the vehicle, the change in power of the motor alters the refrigerant temperature and hence affecting the compressor’s performance. In the present work, 3D Conjugate Heat Transfer simulation of an e-compressor is performed as a complete unit with flow and heat transfer through the motor and compressor. A novel mixed timescale approach for the heat transfer has been developed to simulate the effect of thermal loads on the performance of the compressor. These performance parameters include the outlet temperature, volumetric efficiency, and discharge flow rate of the compressor. The motion of reed valve at the
Ballani, AbhishekPasunurthi, Shyam SundarSrinivasan, ChiranthMaiti, Dipak
The paper presents a preliminary study on a virtual 2-stroke 3-cylinder 0.9 L DI SI supercharged engine running on Hydrogen (H2), able to meet both high performance targets and ultra-low emissions limits (NOx<20 ppm). Combustion is similar to a conventional 4-stroke H2 DI engine, while the design of the cylinder and the actuation law of both intake and exhaust valves are specifically optimized for the 2-stroke cycle. In comparison to a more conventional 2-stroke loop scavenged engine, with piston-controlled ports, the use of poppet valves enables a more flexible control of the gas exchange process and to maintain the same design of a 4-stroke engine for pistons, cylinders block, crankcase and lubrication system. On the other hand, it is more difficult to avoid the short-circuit of the fresh charge, while permeability of the valves becomes quite critical at high engine speed. Therefore, particular care was devoted to the optimization of the intake and exhaust ports geometry, as well as
Caprioli, StefanoVolza, AntonelloMattarelli, EnricoRinaldini, Carlo Alberto
This SAE Recommended Practice establishes uniform Installation Parameters for desiccant Air Dryers for vehicles with compressed air systems
Truck and Bus Brake Supply and Control Components Committee
This specification provides requirements and procedures for gas-pressure leak testing of parts
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This specification covers hand and air operated, solvent and oil spray guns
AMS J Aircraft Maintenance Chemicals and Materials Committee
This standard covers all types of manually operated high pressure oxygen, cylinder shut off valves for use in commercial aircraft. It is intended that the valve shall be attached to a pressure cylinder storing oxygen under a nominal pressure of 12.76 MPa (1850 psig) at 21 °C (70 °F). Upon opening the valve, oxygen will be permitted to discharge from the storage cylinder to the valve outlet and to other downstream components of the oxygen system. It shall also be possible to recharge the cylinder through the valve
A-10 Aircraft Oxygen Equipment Committee
In this paper, an innovative EGR valve, containing an integrated self-cleaning function to mitigate the progressive buildup of carbon deposits, is described. Conventional EGR valves use Butterfly and Poppet mechanisms to open and close a round shaped exhaust gas port with limited ability to remove exhaust carbon deposits from the affected surfaces and mechanical elements. The self-cleaning EGR valve, instead, combining both rotational and linear motions, continuously sweeps its internal passages while delivering the gas flow, removing the carbon deposits before they can adhere to the internal surfaces
Fachechi, Nicola
When a turbocharger exhaust-driven turbine wheel spins fast enough to produce the desired level of boost, a wastegate is typically used to allow the excess exhaust pressure to divert around the turbine wheel. By opening the wastegate (typically boost-pressure referenced), exhaust pressure bypasses the turbo’s turbine wheel to prevent the turbo from reaching an unsafe speed. To actuate wastegate, different actuating mechanisms like pneumatic, vacuum or electric are available, which regulates poppet valve positions e.g. full close, open or partially open. In electronic wastegate valve, exhaust pressure pass through the bypass hole collides with the face of valve causing vibration. Such vibration is transmitted to the wastegate components causing rattle noise. It is challenging to design a wastegate mechanism which can sustain wastegate loads at high temperature and give quiet and robust performance within the full operating range of the engine. In order to improve the rattle noise, the
Patel, Lala RamBaladhandapani PhD, DhanasekarDu, Isaac
The application of Li(Ni0.8Co0.1Mn0.1)O2 (NCM811) cathode-based lithium-ion batteries (LIBs) has alleviated electric vehicle range anxiety. However, the subsequent thermal safety issues limit their market acceptance. A detailed analysis of the failure evolution process for large-format LIBs is necessary to address the thermal safety issue. In this study, prismatic cells with nominal capacities of 144Ah and 125Ah are used to investigate the thermal runaway (TR) characteristics triggered by lateral overheating. Additionally, TR characteristics under two states of charge (SoCs) (100% and 5%) are discussed. Two cells with 100% SoC exhibit similar characteristics, including high failure temperature, high inhomogeneity of temperature distribution, multi-points jet fire, and significant mass loss. Two cells with 5% SoC demonstrate only a slight rupture of the safety valve and the emission of white smoke. However, there is a difference: the 144Ah cell still has a significant temperature rise
Wei, GangZhang, GuangxuChen, SiqiJiang, BoZhu, JiangongHan, GuangshuaiWei, XuezheDai, Haifeng
Taking a closed airbag suspension system as studying objects, the nonlinear dynamic model of the reservoir, compressor, solenoid valve, pipeline and air spring is established. The compressor exhaust volume, solenoid valve flow rate and air spring charging and discharging rate are calculated and compared with experiment to validate the model. Taking pressure difference and height adjustment rate under different working conditions of an airbag suspension as control measures, a control strategy is developed based on the established nonlinear dynamic model. The result indicates that when the vehicle is in curb weight, design weight and GVW (gross vehicle weight), the working time of the compressor can be reduced by 13.6%, 15.1% and 46.5%, respectively, compared with the conventional mode, during a height adjustment cycle. Then a state observer is proposed to estimate the steady-height for reducing the disturbance of measured height from road excitation. According to the required height
Deng, LinLv, HuiShangguan, Wenbin
Technologies transition from dominance to nearly dead at different speeds and for various reasons. That's particularly true for motive power. Pistons, cams and valves are giving way to anodes, cathodes and inverters. Governments and OEMs are pledging hard deadlines (2035!) to end sales of combustion-engine light vehicles. Amid the radical changes, what becomes of the V8 - the engine type that has defined American cars and trucks and has spurred their sales for the past 70 years? It took more than two decades for the automobile to end the horse's reign as the mainstream prime mover. Well into the heyday of Ford's Model T, streets in many U.S. towns remained clogged with horse-drawn vehicles, period photos show
Brooke, Lindsay
HP's binder jetting technology and GKN's manufacturing expertise helped John Deere realize its first 3D-printed metal part for mass production. HP launched its new commercial Metal Jet S100 Solution in September 2022 and two months later showcased the 3D printer for the first time publicly at the Formnext exhibition in Frankfurt, Germany, along with a new John Deere production application. Together with GKN Sinter Metals, John Deere is using the Metal Jet technology to produce thermal diverter valves in the fuel system for its small and midsize tractors assembled in Mannheim, Germany. “Our focus on innovation and sustainability is at the core of everything we do for our customers,” said Dr. Jochen Mueller, manager global digital engineering at John Deere. “We are proud to be among the first in the agricultural industry to leverage the benefits of 3D printing for both prototyping and final-parts production. Leveraging industrial 3D-printing platforms for polymers and metals, we are
Gehm, Ryan
Danfoss Power Solutions claims to increase the productivity of excavators while reducing their fuel consumption by up to 15% by swapping out the machine's main hydraulic pump for a Digital Displacement pump, custom software and controller. The system - appropriately called Dextreme Swap - has been fitted to three 20-ton diesel-powered Volvo EC200 excavators in Ashcourt Group's fleet for field trials, in collaboration with U.K. Volvo dealership SMT. “Our Dextreme Swap system is configured for installation directly into excavators without modification to the existing main control valve,” Leif Bruhn, head of Digital Displacement, Danfoss Power Solutions, told Truck & Off-Highway Engineering. “We offer a simple first step for OEMs to experience and validate the benefits Dextreme systems can bring from a control and integration standpoint.” Danfoss highlighted the Dextreme system at CONEXPO/IFPE 2023 (International Fluid Power Exposition) in Las Vegas
Gehm, Ryan
Excessive internal valve leakage is an inefficiency that worsens upstream system inefficiencies. Effective valve design is the solution. Electric vehicle thermal management requires OEMs and suppliers to control many variables that potentially create excessive heat. Designing thermal-management systems (TMS) to effectively control these variables is critical to overall EV performance. Internal leakage and other coolant-valve performance criteria are among the variables affecting EV performance, most notably driving range. Valve design is fundamental to a robust, thermally efficient and leak-free system, according to engineers at Robertshaw Controls, a specialist in plastic coolant-valve innovation and TMS design
Hokky, Steve
This procedure applies to directional control valves or other valves which in various positions direct or block fluid flow as applied to Off-Road Self-Propelled Work Machines as referenced in SAE J1116
CTTC C1, Hydraulic Systems
Expansion valves are key components of an automotive thermal management system. Recently electronic expansion valves (EXVs) have been replacing conventional thermostatic valves as they offer a finer degree of control. They are operated by a stepper motor and can be based either on a linear or a rotary motion. However, on one hand, the existing linear EXVs with a leadscrew system are not suitable to manage high-pressure and large-diameter port valves, and on the other hand, rotary EXVs have the main disadvantages of having a high mechanical hysteresis and of requiring a dynamic seal which adds cost to the system. This paper proposes then to solve those issues thanks to a new linear concept that provides a new integration on a classic leadscrew linear EXV using a specific radial flux brushless DC (BLDC) motor, a worm gear, and a sensor integration option. The idea behind this is to stop using the conventional coaxial movements of the reducers and to better use the volume of the metal
Billet, LionelLaforge, DamienPetrement, GeoffroyMasson, Gérald
Air Supply Unit (ASU) serves as the pneumatic source for the air suspension system in the passenger car segment. The ASU is an electrically driven oil-free compressor with integrated air dryer to deliver dry air to the suspension system. Solenoid valve, Height Sensor and ECU adjusts the pressure in bellow based on the vehicle load condition. During the lab test, pressure was not building up in the compressor due to delivery valve failure. The type of valve in asu is reed valve type, it is mostly used in the micro compressors due to its low cost, simple structure and light weight configuration. The reed movement is based on the pressure difference between the inlet and the compression chamber. Failure analysis is carried out based on the finite element analysis to identify the root cause, the root cause identified is optimized to prevent the failure. An accelerated test condition is arrived based on the FEA and a tailored series of accelerated tests are carried out to reproduce the
Subramanian, VivekT, Dr. SukumarGovindarasu, Anbarasu
Gasoline compression ignition (GCI) is a promising combustion technology that can help the commercial transportation sector achieve operational flexibility and meet upcoming criteria pollutant regulations. However, high-pressure fuel injection systems (>1000 bar) are needed to enable GCI and fully realize its benefits compared to conventional diesel combustion. This work is a continuation of previous durability studies that identified three key technical risks after running gasoline-like fuel through a heavy-duty, common rail injection system: (i) cavitation damage to the inlet check valve of the high-pressure pump, (ii) loss of injector fueling capacity, (iii) cavitation erosion of the injector nozzle holes. Upgraded hardware solutions were tested on a consistent 400- to 800-hour NATO durability cycle with the same gasoline-like fuel as previous studies. The upgraded pump showed no signs of abnormal wear or cavitation damage to the inlet check valve. In contrast to previous studies
Tzanetakis, TomMedina, RobertoGarg, RajeshPeng, QianMoon, Chi YoungSforzo, Brandon A.Powell , Christopher F.
This SAE Aerospace Recommended Practice (ARP) covers the design and installation requirements for hydraulic systems (up to 8000 psig [56 MPa]) for ground support equipment (GSE). This ARP is derived from AS5440, which provides hydraulic system requirements for aircraft. The recommendations herein are primarily intended for GSE that exchange hydraulic fluid with the aircraft, such as hydraulic service carts, rather than GSE with non-interfacing hydraulic systems. The GSE may be mobile, portable, or stationary
AGE-3 Aircraft Ground Support Equipment Committee
This SAE Aerospace Recommended Practice (ARP) covers the design and installation requirements for hydraulic systems (up to 8000 psig [56 MPa]) for ground support equipment (GSE). The GSE may be portable or stationary
AGE-3 Aircraft Ground Support Equipment Committee
Vehicle electrification is bringing new challenges to the design of components for the automotive sector. New system requirements and functions are forcing either the development of new components or a complete redesign of the existing ones. In the absence of detailed pre-existing knowledge on operating conditions for these components, conservative requirements tend to result in overengineering. System modeling at vehicle level is a valuable approach in these circumstances, which can be used to efficiently estimate such conditions. With modeling, it is possible to define performance targets for components at an early development stage and to verify the impact of component design choices on vehicle performance. In this work we construct a full-vehicle model, which we use to frame the development of coolant distributor valves for electric powertrains. In the first part of the work, we define the topology of the coolant circuit and the relevant interconnected systems (e.g. electrical
Grotti, ErmannoMonsorno, DavideRenzi, Massimiliano
This SAE Recommended Practice is designed to reveal discoloration which may occur when nonmetallic materials used for trimming automobiles are exposed for a limited time to an atmosphere containing hydrogen sulfide
Textile and Flexible Plastics Committee
Nowadays, tractors are frequently used with front-end loaders, dozers and backhoes to cater to various non-agricultural and construction application needs. These applications require frequent shifting of gears due to the constant need for a tractor's forward/reverse direction of motion. Hence, the tractors are fitted with a power shuttle transmission (PST) to cater this need. Power-shuttle transmission (PST) development is a design process that incorporates multiple disciplines such as mechanical, hydraulics, controls and electronics. This paper presents a simulation-based approach to model the power shuttle transmission of the tractor. Firstly, individual components of PST are modelled in detail and then integrated with the complete tractor model. For this, GT-Suite has been used as a simulation platform. The main objective of this simulation was to optimize pressure modulation curves (valve opening and closing characteristics of PST valve) to have less jerk (better drive-ability
Telshinge, PravinPaulraj, Lemuel
As NASA plans for manned missions to Mars, efforts are being made to identify technologies that must be improved to make such trips feasible. Without improvements in valve technologies, propellant and commodity losses will likely make long-duration space missions infeasible. Engineers at NASA's Marshall Space Flight Center have developed a self-aligning poppet for low leakage valves a seat alignment technology that eliminates the need to precisely control interfaces between poppet sealing surfaces and the valve seat seal
Pressure regulating valves are one of the indispensable components in an aircraft. Its application is found in many critical systems such as anti-icing system, cabin pressurization, propulsion system, hydraulic system etc. In this study, the simulation and dynamic analysis of a pressure regulating anti-icing valve is discussed. The valve comprises of an arrangement of sliding piston and pressure chamber to regulate the pressure. It also includes a feedback loop to achieve self-regulation. The valve includes two functional halves for robustness as well as to have some redundant functionality if some components doesn’t function optimally as the operation calls for accuracy as well as precision. The principles behind the working of this valve includes the interaction of physical domains such as mechanical and fluid dynamics. The modeling of this valve is carried out in multi-domain physical state simulation in MATLAB/SIMULINK platform. It is followed by the dynamic analysis to study the
Mallesh, Manoj KumarChandregowda, SunilC, Ganga Reddy
This SAE Aerospace Information Report presents a glossary of terms commonly used in the ground delivery of fuel to an aircraft and pertinent terms relating to the aircraft being refueled
AE-5A Aerospace Fuel, Inerting and Lubrication Sys Committee
Increasing rail pressure is the development trend of high-pressure common rail system. When the rail pressure reaches ultrahigh range, fuel leakage of precision coupling components could have a significant impact on system performance. In order to investigate the effects of system and structure parameters on the leakage characteristics of precision coupling components, guide the design of ultrahigh-pressure common rail system, simulations were carried out. Variation of fuel leakage were studied with different structure and system parameters. A three-dimensional model of oil film with eccentric was developed to simulate eccentric between two parts of coupling component. The leakage in control valve component increases with common rail pressure; however, there is no obvious change in leakage of control piston component with rail pressure. Leakage flow rates in both components increased for about 27 times with the coupling component clearance widths increase from 2 μm to 6 μm, due to the
Zhou, YuhaoLi, GuoxiuLi, HongmengWu, XiaojunXu, Chunlong
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
High speed on-off valves (HSVs) are widely used in advanced hydraulic braking actuators, including regenerative braking systems and active safety systems, which take crucial part in improving the energy efficiency and safety performance of vehicles. As a component involving multiple physical fields, the HSV is affected by the interaction of the fields-fluid, electromagnetic, and mechanical. Since the opening of the HSV is small and the flow speed is high, cavitation and vortex are inevitably brought out so that increase the valve’s noise and instability. However, it is costly and complex to observe the flow status by visual fluid experiments. Hence, in this article a visual multi-physics system simulation model of the HSV is explored, in which the flow field model of the HSV built by computational fluid dynamic (CFD) is co-simulated with the model of hydraulic actuator established by AMESim. Accordingly, the pressure and the opening of the HSV vary with actual working state of the
Meng, AihongGarris, CharlesWei, LingtaoLiu, Haichao
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