Research on heat transfer process plays a very important role in the development of the engine

Due to new technologies such as new combustion system, pressurized, low loss, high strengthen,  Instrumentation ball valve  and the use of alternative fuels, resulting in increased engine heat load. Therefore, the study of heat transfer process plays a very important role in the development of the engine . heat load leads to critical engine parts, such as  Instrument manifolds , pistons, cylinder heads and other thermal fatigue failure, affecting the safety and reliability of the engine is running this paper flow - solid coupling method on the engine exhaust manifold heat stress analyzes, the results of the analysis presented manifold improvements.

The exhaust manifold is the most important part of the engine exhaust system

The exhaust manifold is the most important part of the exhaust system of the engine , the engine is in the middle of the engine exhaust system and the subsequent coupling hub. Since the cylinder head and the engine is directly connected , in the role of high-temperature exhaust gas discharged from the engine , the larger the impact hot exhaust manifold . The complex structure of the exhaust manifold and the temperature distribution is uneven, has long been under the joint action of  Instrument manifolds  and alternating stresses , easily lead to heat crack initiation and expansion , and with the requirements of lightweight vehicles , many of the exhaust manifold by thin-walled tube made ​​. Therefore, in the design and development process of the exhaust manifold , an important guiding significance for its thermal load research . First, based on the engine parameters and  Stainless steel needle valve layout assembly, 3D modeling software application to establish a model of a gasoline engine exhaust manifold . Secondly , the United CFD simulation software and FEA analysis software to predict the exhaust manifold at rated conditions of temperature field, thermal stress and deformation. Finally, the simulation engine in the normal operation state and stop the cooling cycle two , an equivalent plastic strain as the reference standard , the reliability evaluation manifold . The results show that the exhaust manifold is closely related to the complexity of the conditions of temperature distribution and heat and exhaust manifold , exhaust manifold heat stress release focused on the stiffness of the weak structure transition region.

Gasoline stainless steel exhaust manifold airflow performance, thermal stress, thermal mode, performance thermoplastics such as numerical analysis

As cars become a trend and lightweight supercharged engine exhaust temperature brought, stainless steel exhaust manifold has been widely used with gasoline engines. Therefore, this paper has important value engineering studies Gasoline stainless steel exhaust manifold heat load. Analysis, combined with the simulation results to optimize the structure of the exhaust manifold designed to meet product  Stainless steel needle valve  of this article for a gasoline engine airflow performance stainless steel exhaust manifold, heat stress, heat mode, the thermoplastic properties of numerical simulation. Firstly, the flow field through a mathematical model,  Valve manifold  knowledge of fluid dynamics, simulation software for the flow field in the case of the engine exhaust manifold all conditions of different cylinders turned analyzed were obtained pressure distribution and flow lines distribution.

Using fiber grating sensing technology and devices and to achieve a downhole flow control valves without interference signal transmission

Since the microcontroller slice mining technology began to use flow control system for traffic control, significantly increased the rate of oil extraction. In this context, for the precise control and information flow can not interfere with a serious problem,  Instrument valve manifolds  a fiber grating based sensing downhole flow control valve opening detection system. The system uses fiber optic sensing technology and devices, and to achieve a downhole flow control valves  Stainless steel needle valve  signal transmission, can also get traffic information in real time underground, reducing the traditional routine operations. Introduces the research status of downhole flow control valves, flow made ​​using fiber grating detection methods.

The downstream part of the riser is circulating fluidized particle circulation loop

The downstream part of the riser is circulating fluidized particle circulation loop. Mobile phase flow characteristics within the riser of a particle along the high gravity from low-end to high-pressure flow of the lower end, this approach has led to volatility in the flow stream state of diversity and flow processes. As part of a circulating fluidized bed riser particles circulatory system, usually installed with a valve for  Instrumentation ball valve  mass flow rate and control of a circulating fluidized bed, such as fluidized catalytic cracker (FCC) of renewable inclined tube slide valve and pending Health chute slide valve. However, the valve  Instrument needle valve  is different from the gas-solid flow valves generally fluid valve opening change will affect the flow pattern inside the standpipe valve before and after the gas-solid flow valve, causing the valve opening change the particle changes in flow rate is a nonlinear relationship, thereby affecting the regulatory effect of the valve. Riser on the particles flow through the valve orifice similar nesting.

Cone valve stilling basin using turbulent jet turbulent diffusion to deliver energy and mass

Cone valve stilling basin using turbulent jet turbulent diffusion to deliver energy and mass , and ultimately achieve the purpose of energy dissipation . Cone valve has a simple structure , no moving parts, easy maintenance , good sealing and low flow can be precisely controlled a stream and a series of unique characteristics, so frequently used in low flow high head water works to improve conventional brake  High pressure ball valve  control the flow of small, easy to cause vibration chamber is too small, inconvenient construction , aerated water gates and high-speed difficult to control and other shortcomings , but tapered cone valve so that water flows out to the edges along the stilling basin after the flow , water blending intense ,  Instrument valve manifolds  flow , the flow field flow pattern is very complex, especially around the cone valve , water has obvious strong three-dimensional features. ejected flow hydraulics studies has been a research problem, and cone valve , etc. due to the limited complexity of the flow boundary conditions , water flow and a strong three-dimensional nature of modern testing methods for its pilot study , theoretical analysis more difficult. domestic applications is very limited, the project is also due to the imperfect information and its application is less , so the study of both the cone valve engineering applications or further developed in future flow flow pattern and energy dissipation characteristics are of great significance.

Modern theory of turbulence cone valve flow pattern pool stilling basin theoretical analysis

The current status of numerical simulation calculation and application of modern theory of turbulence cone valve flow pattern pool stilling basin theoretical analysis of the stilling basin axis longitudinal section of a mathematical model: a mathematical model for the above discrete finite volume method obtain discrete equations:  Stainless steel needle valve  using the above ADI method, combined with under-relaxation iterative solution of the momentum equations take the relaxation factor 0.5, turbulent kinetic energy, turbulent dissipation rate equation relaxation factor of 0.4; calculation of the pressure field using pressure correction France,  Instrument valve manifolds  factor of 0.8; staggered grid computing grid; solid wall conditions as a function of the rate of a given wall; free surface assuming volatility is not, press the "rigid lid" hypothetical treatment; downstream outlet assumes that the turbulence has reached the autocorrelation balance. Calculation process, according to the conical valve stilling basin own characteristics, diffusion and source terms were also owe relaxation, diffusion and relaxation factor source terms are taken as 0.5.