scholarly journals CALCULATION OF PARAMETERS OF CHANNEL THROTTLING OF EXPENSIVE ELEMENTS OF FIRMWARE

2020 ◽  
pp. 50-53
Author(s):  
V. A. Saninsky ◽  
E. A. Fedyanov ◽  
E. N. Nesterenko
Keyword(s):  
Flow Rate ◽  
Economic Efficiency ◽  
Outer Surface ◽  
Coolant Flow ◽  
Mechanical Processing ◽  
Liquid Coolant ◽  
Calculation Of Parameters ◽  
Advantages And Disadvantages ◽  
Processing Modes ◽  
Pipe Blanks

The article considers possible options for supplying coolant to the cutting and deforming teeth of multi-pronged firmware for processing deep holes. The advantages and disadvantages of each scheme are indicated. It is noted that when the lubricant-cooling liquid (coolant) is pushed through straight or screw slotted grooves made on the outer surface of the mandrel teeth, "damping pads" are created on the surface to be processed, which improve the mandrel process and reduce wear of the stitches for processing deep holes. For each of the schemes, a method for calculating the coolant flow rate is described, depending on the parameters of the slotted grooves for the coolant flow and the pressure of its supply. The ability to calculate the consumption of coolant through the cutting and deforming teeth of multi-toothed stitches allows you to correctly assign processing modes and, thereby, increase the technical and economic efficiency of mechanical processing of long pipe blanks.

Effect of Outer Fin Axial Gap on the Sealing Effectiveness and Fluid Dynamics of Radial Rim Seal

2017 ◽  
Author(s):  
Zhigang Li ◽  
Jun Li ◽  
Liming Song ◽  
Qing Gao ◽  
Xin Yan ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Flow Rate ◽  
Gas Turbines ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Coolant Flow ◽  
Coolant Flow Rate ◽  
Navier Stokes ◽  
Hot Gas

The modern gas turbine is widely applied in the aviation propulsion and power generation. The rim seal is usually designed at the periphery of the wheel-space and prevented the hot gas ingestion in modern gas turbines. The high sealing effectiveness of rim seal can improve the aerodynamic performance of gas turbines and avoid of the disc overheating. Effect of outer fin axial gap of radial rim seal on the sealing effectiveness and fluid dynamics was numerically investigated in this work. The sealing effectiveness and fluid dynamics of radial rim seal with three different outer fin axial gaps was conducted at different coolant flow rates using three-dimensional Reynolds-Averaged Navier-Stokes (RANS) and SST turbulent model solutions. The accuracy of the presented numerical approach for the prediction of the sealing performance of the turbine rim seal was demonstrated. The obtained results show that the sealing effectiveness of radial rim seal increases with increase of coolant flow rate at the fixed axial outer fin gap. The sealing effectiveness increases with decrease of the axial outer fin gap at the fixed coolant flow rate. Furthermore, at the fixed coolant flow rate, the hot gas ingestion increases with the increase of the axial outer fin gap. This flow behavior intensifies the interaction between the hot gas and coolant flow at the clearance of radial rim seal. The preswirl coefficient in the wheel-space cavity is also illustrated to analyze the flow dynamics of radial rim seal at different axial outer fin gaps.

Characteristics Analysis of SCWR During Partial Loss of Reactor Coolant Flow Transient

2012 ◽  
Author(s):  
Juan Chen ◽  
Tao Zhou ◽  
Zhousen Hou ◽  
Canhui Sun
Keyword(s):  
Flow Rate ◽  
Transient Analysis ◽  
Coolant Flow ◽  
Partial Loss ◽  
Initial Flow ◽  
Reactor Coolant ◽  
Loss Of Coolant ◽  
Characteristics Analysis ◽  
And Control ◽  
Supercritical Water Cooled Reactor

Partial loss of reactor coolant flow is one of the most important transients for safety analysis of supercritical water-cooled reactor (SCWR). Taking the super LWR concept provided by Japan as research object, transient analysis of partial loss of coolant flow rate is given by coupled neutronics and thermal hydraulics calculation method. The results show that, when 5% partial loss of coolant flow is happening, maximum cladding temperature would increase firstly with the decreasing of fuel channel inlet coolant flow. Then followed with the neutronic feedback and control operation, maximum cladding temperature decreases and finally return to normal. When 50% partial loss of coolant flow is happening, a scram signal will be given to ensure system safety, but the maximum cladding temperature still shows a significant increase early. On this basis, sensitivity analysis is performed considering the influence of core power and main coolant flow. It is found that maximum peaking value increases significantly following the initial flow rate decreasing, but shows a very little increase caused by core power increasing.

Simulation on the Temperature Field of Milling Roller Using Fluent Software

2015 ◽  
Vol 1095 ◽  
pp. 846-850
Author(s):  
Min Wang ◽  
Ke Ping Zhang ◽  
Feng Wei Zhang
Keyword(s):  
Temperature Field ◽  
Flow Rate ◽  
Coolant Flow ◽  
Coolant Flow Rate ◽  
Roller Surface ◽  
Fluent Software ◽  
The Law

In order to study the law between the internal coolant flow rate and the temperature of milling roller, the temperature field of water-cooled roller was simulated with Fluent software. The results showed that with the increase of the coolant flow rate, the temperature on roller surface decreased, but after the flow rate of coolant increased to 3.5 kg/s, the temperature of roller maintained invariant almost, so 3.5 kg/s was the best flow rate.

Numerical Studies on the Effect of Tip Clearance and Tip Cooling Flow on Endwall Losses of an Unshrouded Axial Turbine Rotor

2013 ◽  
Author(s):  
K. Asgar Ali ◽  
Quamber H. Nagpurwala ◽  
Abdul Nassar ◽  
S. V. Ramanamurthy
Keyword(s):  
Flow Rate ◽  
Layer Growth ◽  
Coolant Flow ◽  
Tip Clearance ◽  
Coolant Flow Rate ◽  
Total Efficiency ◽  
Turbine Stage ◽  
Suction Surface ◽  
Axial Turbine ◽  
Ejection Rate

This paper deals with the numerical investigations on a low pressure axial turbine stage to assess the effect of variation in rotor tip clearance and tip coolant ejection rate on the end wall losses. The rotor, along with the NGV, was modeled to represent the entire turbine stage. The CFX TASCflow software was used to perform steady state analysis for different rotor tip clearances and different tip coolant ejection rates. The locations of the cooling slots were identified on the blade tip and the coolant ejection rate was specified at these areas. The simulations were carried out with tip clearances of 0%, 1% and 2% of blade height and ejection flow rates of 0.5%, 0.75% and 1% of main turbine flow rate. It is shown that the size and strength of the leakage vortex is directly related to the tip clearance. The reduction in efficiency is not in linearity with the tip clearance owing to the effect of boundary layer growth on the end walls. Introduction of the tip coolant flow shows increased total–total efficiency compared to that of the uncooled tip. This is attributed to a reduction in the strength of the leakage vortex due to reduced cross-flow over the tip clearance from pressure surface to suction surface. At a coolant flow rate of 0.75% of the main flow rate, there is significant increase in efficiency of about 0.5%. Optimum tip clearance and coolant flow rate are obtained based on the results of the present analysis.

Effects of Endwall Film Coolant Flow Rate on Secondary Flows and Coolant Mixing in a First Stage Nozzle Guide Vane

2021 ◽  
Author(s):  
Mahmood Alqefl ◽  
Kedar Nawathe ◽  
Pingting Chen ◽  
Rui Zhu ◽  
Yong Kim ◽  
...  
Keyword(s):  
Flow Rate ◽  
Guide Vane ◽  
Secondary Flows ◽  
Coolant Flow ◽  
Coolant Flow Rate ◽  
Nozzle Guide Vane ◽  
Nozzle Guide

Heat Removal and Thermal Stabilization of High-temperature Surfaces by a Dispersed Coolant Flow

Vestnik MEI ◽  
2021 ◽  
pp. 19-26
Author(s):  
Valentin S. Shteling ◽  
◽  
Vladimir V. Ilyin ◽  
Aleksandr T. Komov ◽  
Petr P. Shcherbakov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Flux Density ◽  
Flow Rate ◽  
Heat Flux Density ◽  
Coolant Flow ◽  
Transfer Coefficients ◽  
Stationary Heat ◽  
Heat Transfer Coefficients ◽  
Stationary Heat Transfer

The effectiveness of stabilizing the surface temperature by a dispersed coolant flow is experimentally studied on a bench simulating energy intensive elements of thermonuclear installations A test section in which the maximum heat flux density can be obtained when being subjected to high-frequency heating was developed, manufactured, and assembled. The test section was heated using a VCh-60AV HF generator with a frequency of not lower than 30 kHz. A hydraulic nozzle with a conical insert was used as the dispersing device. Techniques for carrying out an experiment on studying a stationary heat transfer regime and for calculating thermophysical quantities were developed. The experimental data were obtained in the stationary heat transfer regime with the following range of coolant operating parameters: water pressure equal to 0.38 MPa, water mass flow rate equal to 5.35 ml/s, and induction heating power equal to 6--19 kW. Based on the data obtained, the removed heat flux density and the heat transfer coefficients were calculated for each stationary heat transfer regime. The dependences of the heat transfer coefficient on the removed heat flux density and of the removed heat flux density on the temperature difference have been obtained. High values of heat transfer coefficients and heat flux density at a relatively low coolant flow rate were achieved in the experiments.

Investigation of the modification effect on performance properties of cast iron molds

2021 ◽  
pp. 23-28
Author(s):  
V. A. Gulevskiy ◽  
◽  
S. N. Tsurikhin ◽  
V. V. Gulevskiy ◽  
N. Yu. Miroshkin ◽  
...  
Keyword(s):  
Cast Iron ◽  
Outer Surface ◽  
Heating Temperature ◽  
Primary Aluminum ◽  
Operating Conditions ◽  
Senior Lecturer ◽  
Advantages And Disadvantages ◽  
Stress And Deformation ◽  
Consumable Electrodes

Research is devoted to the influence of the technological method of modifying gray cast iron for the manufacture of steel casting molds. Heavy operation imposes stringent requirements both on the design of molds and on the materials from which they are made. They reliably withstand the effects of steel poured into them, having a temperature of 1600–1700 °C, thermal shock, which is directly proportional to this temperature, as well as significant effects of cyclic thermal stress and deformation. Specific operating conditions of molds (high heating temperature, their installation on movable and stationary ditches, intensive traffic flows, etc.) complicate the necessary processes directly during their operation. Modeling geometric shapes on a scale of geometric similarity 1:10. Tests were carried out on molds cast from cast iron for consumable electrodes, modified with ferrosilicon (FS65 GOST 1415-93), primary aluminum A99 (GOST 11069-2001), vanadium slag (SHVD-1 TU14-11-178-86), FSB-30) and silicomishmetal (SIMISH-1). These modifiers were chosen for modification, as they are widely used in production. Thus, the conducted studies of the nature of the deformation of the walls of the molds and the stress-strain state on models made of gray and modified cast iron make it possible to assess the advantages and disadvantages of the resulting structure and shape of graphite. Further, the methods of the rational formula of the outer surface of profiled and sheet molds are used, having predetermined the nature of destruction in advance. The use of thin-walled used rational forms can significantly reduce their specific consumption. The study of the quality of the metal cast into the experimental curved outer surface showed that the macrostructure of the metal of the experimental and ordinary ingots is the same. The work was attended by N.V Markina, senior lecturer at the Dept. of Machines and Foundry Technology, Volgograd State Technical University.

Analytical Model Quantifying the Net Coolant Flow Rate to a Microstructured Copper Surface validated with Two-Phase PIV Measurements

2021 ◽  
Author(s):  
Matt Harrison ◽  
Joshua Gess
Keyword(s):  
Heat Transfer ◽  
Analytical Model ◽  
Flow Rate ◽  
Circular Disk ◽  
Nucleate Boiling ◽  
High Heat ◽  
Heat Fluxes ◽  
Coolant Flow ◽  
Coolant Flow Rate ◽  
Two Phase

Abstract Using Particle Image Velocimetry (PIV), the amount of fluid required to sustain nucleate boiling was quantified to a microstructured copper circular disk. Having prepared the disk with preferential nucleation sites, an analytical model of the net coolant flow rate requirements to a single site has been produced and validated against experimental data. The model assumes that there are three primary phenomena contributing to the coolant flow rate requirements at the boiling surface; radial growth of vapor throughout incipience to departure, bubble rise, and natural convection around the periphery. The total mass flowrate is the sum of these contributing portions. The model accurately predicts the quenching fluid flow rate at low and high heat fluxes with 4% and 30% error of the measured value respectively. For the microstructured surface examined in this study, coolant flow rate requirements ranged from 0.1 to 0.16 kg/sec for a range of heat fluxes from 5.5 to 11.0 W/cm2. Under subcooled conditions, the coolant flow rate requirements plummeted to a nearly negligible value due to domination of transient conduction as the primary heat transfer mechanism at the liquid/vapor/surface interface. PIV and the validated analytical model could be used as a test standard where the amount of coolant the surface needs in relation to its heat transfer coefficient or thermal resistance is a benchmark for the efficacy of a standard surface or boiling enhancement coating/surface structure.

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