Browse Topic: Valves
Aligned with the “3060 dual carbon” goal, the rapid growth of new energy installation capacity in China’s western high-altitude regions has caused an urgent demand for UHV converter station construction. This paper suggests a prefabricated structural system by using embedded ear-shaped tongue-and-groove UHPC wall-column connections to meet the challenges of traditional cast-in-place concrete firewalls, such as prolonged construction periods and difficulty in quality control in harsh environments. The seismic performance of the connection was investigated through pseudo-static tests and finite element analysis. The results show that failure mainly occurs on the wall–column interface, with cracks mainly appearing at the wall panel corners. The scaled model demonstrated full hysteresis loops, indicating stable energy dissipation. The ear-shaped tongue-and-groove connection showed superior initial stiffness and ultimate load-bearing capacity (404.3 kN) compared with the straight-type connection (177.5 kN). An increase in the semicircular diameter improved load capacity, while the axial compression ratio had little effect. This study proposes a theoretical reference for the design and application of prefabricated valve hall structures in high-altitude regions.
A valve developed by NASA Stennis Space Center consists of a solid piston floating in a medium to control the flow stream. The piston is designed to be axially and radially balanced within the flow stream whether the valve is in the open or closed position. The only force imparted onto the piston is that which the operator chooses to input on to it.
A computational study using the Volume of Fluid (VOF) method in SimericsMP+ was conducted to investigate fuel sloshing in automotive fuel tanks under both crash and sudden stop conditions. The SEALs method was employed to rapidly generate the fuel tank mesh, enabling efficient simulation setup. At the outset, a benchmark sloshing case was simulated and compared against experimental data, showing excellent agreement to validate the simulation method. This simulation method was then applied to the fuel tank sloshing scenarios mimicking crash and sudden stop conditions. The study initially focused on a crash scenario in which fuel waves impact valves, pumps, and other internal structures. Capturing these localized impact forces is critical for evaluating the risk of component failure and potential leakage. A baffle-equipped tank was simulated and compared with sensor data. Results show that the computed shock forces on valves and baffles closely matched the measurements, demonstrating the high accuracy of the CFD method in predicting crash safety performance and confirming the effectiveness of baffles in reducing fuel wave impacts. The validated framework was then applied to four new unbaffled tank designs to assess NVH performance during low-speed sudden stop maneuvers. Pressure fluctuations on tank walls, which are directly linked to cabin noise, were analyzed and compared against reference pressure measurements from physical tests to ensure compliance with NVH standards. Simulations revealed significant pressure peaks in certain designs, indicating sub-optimal acoustic performance and highlighting how the absence of internal columns or baffles amplifies wave propagation and surface loading. The computational strategy presented in this study provides a powerful tool for evaluating both crash safety and NVH behavior early in the design process. By delivering accurate predictions before physical prototypes are built, it helps guide fuel tank design development, reduces reliance on costly testing, and minimizes the risk of late-stage design failures.
Off-highway equipment operates in an environment defined by extremes - extreme loads, extreme duty cycles, extreme temperatures and extreme expectations. OEMs and fleet operators face mounting pressure to deliver more power, more uptime and more precision from platforms that are becoming increasingly compact, intelligent and complex. Whether the task is hauling, lifting, dumping, clearing or moving materials, the equipment must deliver consistent, reliable performance without compromise. This pressure is reshaping the mobile-hydraulic ecosystem. The industry is steadily shifting away from piecemeal systems and toward integrated, intelligent power architectures that maximize efficiency across the entire vehicle. Leaders in this space, Eaton among them, demonstrate how a system-level approach to PTOs, hydraulic pumps and control valves is enabling a new generation of off-highway innovation.
The Container trailers are used worldwide to transport goods & materials especially e-commerce applications with valuable materials. These container trailers are presently locked with a mechanical locking system and often broken and unlocked by unauthorized people. During transportation time, the driver stops the vehicle for natural calls, food or any other breakdown, the attempt is made to steal the materials. Many cases were known only after damages are done. It has become a serious issue nowadays in the transportation industry. To avoid these problems, we have designed and developed a system that operates pneumatically with digital locking control. The system is designed to ensure proper safety by rigid mechanical locking. It is actuated by a pneumatic system consisting of Directional control valve & pneumatic cylinders. The lock and unlock inputs are given through digitally and the digital controller provides the appropriate input to solenoid operated direction control valve. Based on the position of Direction control valves, the pneumatic cylinders lock or unlock the mechanical locking system. The safety system is integrated along with the digital pin locking. The system is designed with the concept of fool-proof and fail-safe. In the event of no Pneumatic or electrical supply failure, the system remains in lock condition only. Except the authorized person, others cannot open the containers without the authorization pin. Also, the system provides a technologically improved version of the safety locking system like geo-fencing. We can lock and unlock the container with geological identity. The safety locking system improves confidence among the transporters and ensures safety at the highest level.
Hydrogenated nitrile butadiene rubbers (HNBR) and their derivatives have gained significant importance in automotive compressed natural gas (CNG) valve applications. In one of the four-wheelers, CNG valve application, HNBR elastomeric diaphragms are being used for their excellent sealing and pressure regulation properties. The HNBR elastomeric diaphragm was developed to sustain CNG higher pressure However, it was found permanently deformed under lower pressures. In this research work, number of experiments was carried out to find out the primary root cause of diaphragm permanent deformation and to prevent the failure for safe usage of the CNG gas. HNBR diaphragm deformation investigation was carried out using advanced qualitative and quantitative analysis methods such as Soxhlet Extraction Column, Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA). For this purpose, we have carried out experiments on OK (HNBR diaphragm with higher bar pressure) and field-failed diaphragms (HNBR diaphragm deformed after lower bar CNG pressure). We have found that OK and Field failed diaphragms have different filler concentrations and uneven dispersion and distribution. Also, the crosslinking density of the failed Field diaphragms was observed in declining order in comparison with the OK diaphragms. TGA and SEM analysis revealed the filler concentration and morphology of the diaphragms. The chemical nature and thermal properties have been analysed using FTIR and DSC analysis techniques. The Soxhlation extractions study helped to understand the crosslinking density of OK and field failure diaphragms. Preventive measures have been implemented to mitigate the HNBR diaphragm permanent deformation issue.
In today's dynamic driving environments, reliable rear wiping functionality is essential for maintaining safe rearward visibility. This study sharing the next-generation rear wiper motor assembly that seamlessly integrates the washer nozzle, delivering improved performance alongside key benefits such as better Buzz, Squeak, and Rattle (BSR) characteristics, reduced system complexity, cost savings, and enhanced perceived quality. This integrated design simplifies the hose routing which improves the compactness and the efficiency of the design. This also enhances the spray coverage and minimizes the dry wiping unlike the traditional systems that position the washer nozzle separately. A non-return valve (NRV) is incorporated to eliminate spray delays ass it maintains consistent water flow giving cleaning effectiveness. Since this makes the nonfunctional parts completely leak proof due to the advanced sealing, it increases the durability and reliability in long run. As this proposal offers a sustainable solution, it can be considered as the new benchmark in rear wiper technology.
Eaton's decompression engine braking technology for medium and heavy-duty diesel engines delivers high braking power and provides several advantages to the commercial truck owner. Eaton offers rocker arm-based 1 stroke, 1.5 stroke, and 2 stroke systems for overhead cam and cam in block engine architectures. The Compression Release (CR) engine brake avoids overheating and fading of primary friction brake. It reduces or eliminates the need for a driveline retarder. One of the failure modes for Engine Brake (EB) system is excessive lateral displacement of the exhaust valve, caused by non-uniform pressure distribution across the valve during Brake Gas Recirculation (BGR) and Compression Release modes. This excessive deformation is referred to as Valve Wagging. Valve wagging significantly affects the structural stability of the engine brake mechanism. Analyzing its behavior is essential to minimize excessive wear on valve guide and Valve Seat Insert in new designs. Since evaluating the valve wagging phenomenon through prototype testing is both costly and time-consuming, a validated analytical approach was developed. A coupled CFD and structural dynamics analysis approach was developed to predict valve wagging phenomena. This approach includes simulating transient valve motion using a dynamic mesh technique, capturing the influence of valve motion on surrounding flow-field, and assessing the impact of flow field on valve structural displacement. The developed methodology was validated by comparing simulated valve lateral displacement with experimental results, showing good agreement between the two.
The height valve adjusting rod is an important part of the suspension system, used to adjust the height of the train to adapt to the train through the curve, slope or uneven track when the height valve adjusting rod fracture failure, the train’s suspension system can not be adjusted normally, may lead to the height of the train is too high or too low, affecting the stability of the train and the driving safety. In this paper, an underground vehicle height valve adjusting rod fracture failure of the problem was studied and analysed, the specific conclusions are as follows: height valve adjusting rod there are two main vibration frequency, 60Hz and 340Hz, 60Hz main frequency has always existed, and 340Hz vibration frequency are present in part of the interval, but also caused by the vehicle vibration of the main reason for the local larger; height valve adjusting rod stress there is also a significant vibration The main frequency of 340Hz, similar to the vibration characteristics of the vibration response, the main frequency of vibration only exists in part of the interval, and is the main reason for the stress is locally large; comprehensive consideration of the vehicle vibration state and stress level, 340Hz rail grinding frequency is the main reason for the height valve regulator vibration level and the stress level is obviously increased, but also led to the failure of the height valve regulator; can be achieved by grinding rail Or improve the structure of the crossbar so that the inherent modal frequency of the crossbar is far away from the wave abrasion frequency, which can provide a certain reference significance for other urban rail vehicle projects to solve such problems.
This paper presents transient, complex, moving mesh, 3-D CFD analysis of an intebrake lubrication oil circuit for predicting flow performance. Intebrake is a mechanism for improving braking performance during over speeding conditions. The mechanism briefly opens the exhaust valve at the end of a compression stroke with a small valve lift and releases the compressed gases, thereby helping in quick application of the brake. There is no fueling during the process and hence, no combustion induced pressure rise which helps in quick application of the brake. During the intebrake operation, opening of the exhaust valve is achieved by using a complex lube oil circuit inside the exhaust rocker lever. The intebrake lube oil circuit consists of various spring-operated valves with micro-sized clearances, high oil pressure generation up to ~ 250 bar, 3-D movement of the mechanism components, and it is a transient operation. The 3-D movement consists of simultaneous rotational and translational motions with dynamic motions due to net force balance between spring and fluid forces. All these factors make the simulation an absolute need as testing is extremely costly and difficult due to tight space constraints around the mechanism. The 3-D CFD model with automatic intebrake ON and OFF operations makes dynamic mesh motion more complex. In the current work, 3-D CFD simulation approach is developed which can model the intebrake operation by considering dynamic mesh, small clearances, and oil compressibility effects. The predicted intebrake lube system oil pressure is compared with transient, crank angle based test data and the results are found to be in good correlation. This approach has helped in better understanding of the intebrake response to variation of different design parameters and resolving field failures. After a single cylinder intebrake model validation, it has been extended to modeling 6-cylinders and integrated with engine 3-D CFD lube system as well.
The main purpose of the semi-active hydraulic damper (SAHD) is for optimizing vehicle control to improve safety, comfort, and dynamics without compromising the ride or handling characteristics. The SAHD is equipped with a fast-reacting electro-hydraulic valve to achieve the real time adjustment of damping force. The electro-hydraulic valve discussed in this paper is based on a valve concept called “Pilot Control Valve (PCV)”. One of the methods for desired force characteristics is achieved by tuning the hydraulic area of the PCV. This paper describes a novel development of PCV for practical semi-active suspension system. The geometrical feature of the PCV in the damper (valve face area) is a main contributor to the resistance offered by the damper. The hydraulic force acting on the PCV significantly impacts the overall performance of SAHD. To quantify the reaction force of the valve before and after optimization under different valve displacements and hydraulic pressures were simulated using comprehensive three-dimensional (3D) Computational Fluid Dynamics (CFD) methods. For computational model validation purposes, PCV prototypes of the optimized design were procured and tested on a suitable test rig to obtain the hydraulic damping force characteristics at different input current signals. The proposed virtual development method using CFD simulation allows early selection of semi-active valve before physical prototype build. The performance characteristics of a prototype derived from the optimal design of the SAHD assembly are presented. The simulation and experimental results show an improvement in the semi-active damping force under certain conditions. This capability is crucial for systems like SAHD, where rapid and precise control of oil flow is essential.
University of Freiburg, Freiburg, Germany
Innovators at NASA Johnson Space Center have developed an adjustable thermal control ball valve (TCBV) assembly which utilizes a unique geometric ball valve design to facilitate precise thermal control within a spacesuit. The technology meters the coolant flow going to the cooling and ventilation garment, worn by an astronaut in the next generation space suit, that expels waste heat during extra vehicular activities (EVAs) or spacewalks.
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 is subjected to high velocity and impact force during this short time. A 1-D AMESim representation of the compressor has the reed valve modeled as an equivalent spring mass system. 3-D static structural analysis is performed using FEA tool to predict the stiffness, natural frequency and equivalent mass which acts as the input to the 1-D model. The overall performance of the compressor is then predicted through the 1-D Model simulation. The pressure data from this 1-D model is fed back to FEA to perform a 3-D transient dynamic analysis. The impact velocity and dynamic stresses induced during valve operation is studied to ensure reed valve durability. Optimization of the design parameters of reed valve is performed by synergistically combining the key insights from the AMESim performance outputs as well as the stiffness and dynamic stress prediction from FEA.
Items per page:
50
1 – 50 of 2969