scholarly journals Heat Transfer in Reciprocating Spiral Tube with Piston Cooling Application

2002 ◽  
Vol 45 (2) ◽  
pp. 379-391 ◽  
Author(s):  
Shyy Woei CHANG ◽  
Shiou Fuu CHIOU
Keyword(s):  
Heat Transfer ◽  
Spiral Tube ◽  
Piston Cooling

Heat Transfer in Reciprocating Planar Curved Tube With Piston Cooling Application

2005 ◽  
Vol 128 (1) ◽  
pp. 219-229 ◽  
Author(s):  
Shyy Woei Chang ◽  
Yao Zheng
Keyword(s):  
Heat Transfer ◽  
Local Heat Transfer ◽  
Local Heat ◽  
Interactive Effects ◽  
Experimental Conditions ◽  
Nusselt Numbers ◽  
Curved Tube ◽  
The Individual ◽  
Cooling Passage ◽  
Piston Cooling

This paper describes an experimental study of heat transfer in a reciprocating planar curved tube that simulates a cooling passage in piston. The coupled inertial, centrifugal, and reciprocating forces in the reciprocating curved tube interact with buoyancy to exhibit a synergistic effect on heat transfer. For the present experimental conditions, the local Nusselt numbers in the reciprocating curved tube are in the range of 0.6–1.15 times of static tube levels. Without buoyancy interaction, the coupled reciprocating and centrifugal force effect causes the heat transfer to be initially reduced from the static level but recovered when the reciprocating force is further increased. Heat transfer improvement and impediment could be superimposed by the location-dependent buoyancy effect. The empirical heat transfer correlation has been developed to permit the evaluation of the individual and interactive effects of inertial, centrifugal, and reciprocating forces with and without buoyancy interaction on local heat transfer in a reciprocating planar curved tube.

Numerical and experimental investigation on the effect of the two-phase flow pattern on heat transfer of piston cooling gallery

2019 ◽  
Vol 20 (5) ◽  
pp. 507 ◽  
Author(s):  
Lijun Deng ◽  
Jian Zhang ◽  
Guannan Hao ◽  
Jing Liu
Keyword(s):  
Heat Transfer ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Unstable Wave ◽  
Fluid Viscosity ◽  
Phase Flow ◽  
Two Phase ◽  
Flow Process ◽  
The Impact ◽  
Piston Cooling

To study factors affecting the formation and conversion of two-phase flow pattern as well as the heat transfer of piston cooling gallery, a transient visual target test bench was set up to research the oscillatory flow characteristics in the cooling gallery under idle condition of the engine. The computational fluid dynamics (CFD) was employed while dynamic mesh technology, SST k–ω turbulence model and volume of fluid (VOF) two-phase flow model were applied to simulate the flow process of piston cooling gallery so as to predict the distribution pattern of two-phase flow. Simulation results were in good agreement with that experimentally obtained. It was observed that in the reciprocating movement of the piston, the action of two-phase flow oscillation was severe, forming some unstable wave flows and slug flows. Results show that under the same pipe diameter, the increase of fluid viscosity results in the decrease of amplitude and the increase of the liquid slugs number as well as the enhancement on heat transfer effect. In addition, it was revealed that injection pressure has little effect on the two-phase flow pattern. However, when the pressure is reduced, the change of the liquid phase is weakened and the locations of flow pattern transition move towards to the behind, thus the impact on the heat transfer is also faint.

The Numerical Calculation of the Temperature Field of Water-Wall Tube of the Supercritical Boiler under Near-Critical Condition

2014 ◽  
Vol 875-877 ◽  
pp. 1876-1880
Author(s):  
Chun Yan Li
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Working Conditions ◽  
Thermal Calculation ◽  
Spiral Tube ◽  
Heat Transfer Deterioration ◽  
Water Wall ◽  
Working Medium ◽  
The Mean ◽  
Water Wall Tube

The spirally water wall are distributed on the plane and divided into seven sections. The mean heat flux of each section is determined using furnace thermal calculation in sections. The value of the pressure and temperature concerning the working medium at inlet and outlet of each tube are established by calculating enthalpy increasing. The vaporizing processes of the working medium in the spiral tube under the three working conditions: 70%BMCR, 65%BMCR and 60%BMCR are analyzed. The state of the working medium and the possibility of the heat transfer deterioration are estimated. More reliable references are provided for the appearance of the heat transfer deterioration.

Heat Transfer in Supercritical Steam Flowing Through Spiral Tubes

2020 ◽  
Vol 142 (11) ◽  
Author(s):  
Deepak Kumar Kanungo ◽  
Sachin Kumar Shrivastava ◽  
Nand Kumar Singh ◽  
Kirti Chandra Sahu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Three Dimensional ◽  
Tangential Velocity ◽  
Thermal Conditions ◽  
Strong Relationship ◽  
High Heat ◽  
High Heat Flux ◽  
Straight Tube ◽  
Spiral Tube

Abstract We investigate heat transfer in supercritical steam flowing in a spiral tube by conducting three-dimensional numerical simulations. The current numerical solver has been validated with the existing experimental results, and simulations are performed by varying different geometric parameters of a spiral tube. The flow dynamics and heat transfer in a spiral tube are compared against those in a straight tube. For the parameters range considered in the present study, it is found that the heat transfer coefficient (HTC) in the spiral tube is 29% higher than that in the case of a straight tube for the same flow and thermal conditions. Our results indicate that the tangential velocity component resulting due to the spiraling effect of the steam is the primary reason for the enhancement of the HTC value. It is observed that while the HTC in a spiral tube is inversely related to the spiral diameter, it does not exhibit a strong relationship with the spiral pitch. Moreover, three existing heat transfer correlations are evaluated under the spiral flow condition and it is observed that none of them can calculate the HTC value accurately in spiral tubes. Using the Buckingham π-theorem, three modified correlations are proposed for the low, moderate, and high heat flux regimes, which accurately predict the wall temperature and HTC of supercritical steam in spiral tubes in all the heat flux regimes. The correlations have an error band of less than ±20%.

Study on the Conical Spiral Tube Bundle Heat Exchangers with Pulsation Flow Generator Structure

2011 ◽  
Vol 143-144 ◽  
pp. 698-702 ◽  
Author(s):  
Meng Ran Ge ◽  
Ke Yan ◽  
Pei Qi Ge ◽  
Jun Gao
Keyword(s):  
Heat Transfer ◽  
Natural Frequency ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Tube Bundle ◽  
Elastic Tube ◽  
Transfer Performance ◽  
Spiral Tube ◽  
Flow Generator ◽  
Planar Elastic Tube Bundle

Elastic tube bundles are universally used in heat transfer enhancement by flow-induced vibration in heat exchangers, and the study of the heat transfer performance is of importance. The structure of conical spiral tube bundle heat exchanger was introduced first, and the structure of pulsation flow generator was also introduced. The frequency of pulsation flow was discussed. Finally, in condition of same shell side diameter, the heat transfer and natural frequency of the conical spiral tube bundle were compared with the planar elastic tube bundle. The results show that the natural frequency of conical spiral tube bundle was smaller, the heat transfer performance of conical spiral tube bundle was better than the planar elastic tube bundle.

scholarly journals Numerical study on heat transfer and flow resistance characteristics of multi-head twisted spiral tube

2021 ◽  
pp. 206-206
Author(s):  
Zhiqun Zheng ◽  
Fayi Yan ◽  
Lei Shi
Keyword(s):  
Heat Transfer ◽  
Numerical Calculation ◽  
Cross Section ◽  
Heat Transfer Performance ◽  
Numerical Study ◽  
Smooth Tube ◽  
Transfer Performance ◽  
Spiral Tube ◽  
Inside Diameter ◽  
The Cross

A numerical calculation model of multihead twisted spiral tube (MTST) was established. In the range of Reynolds number from 5000 to 35000, the influence of different twisted structure on the flow and heat transfer characteristics of the MTST was studied by numerical calculation. Numerical calculation results indicate that the Nusselt number and friction coefficient increase with the increase in the ratio of outside and inside diameter of the cross-section, the increase in the number of twisted nodes, and the increase in the number of twisted spiral tube heads. Under the condition of the same spiral structure and the same hydraulic diameter, the heat transfer performance of the MTST is better than that of the spiral smooth tube. In addition, through artificial neural network (ANN) analysis, the ratio of outside and inside diameter of the cross-section, number of twisted nodes, and the number of twisted spiral tube heads were optimized to promote the comprehensive heat transfer performance. The performance evaluation criterion is the highest when the ratio of outside and inside diameter of the cross-section is 25/22.5, the number of twisted nodes is 3, and the number of twisted spiral tube heads is 3, which is 1.849 of the spiral smooth tube.

Experimental and Numerical Analysis of the Piston Cooling Jet’s Performance

2010 ◽  
Author(s):  
Mohamad Izadi ◽  
Seyed Vahid Hosseini ◽  
Seyed Shahab Alaviyoun ◽  
Seyed Mostafa Agha Mirsalim
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Hot Spots ◽  
Thermal Environment ◽  
Test Rig ◽  
Piston Crown ◽  
Sharp Edges ◽  
Oil Jet ◽  
Piston Cooling

Recently, with development in the output power and material cost efficiency, the value of thermal and mechanical stress on many engine parts such as piston is increased. On the other hands, the strength of aluminum alloys used for piston manufacturing decreases with temperature. So, for lightweight pistons, the strength reduction should be minimized to maintain the mechanical integrity of the part. This drives piston designers to use strong and lightweight materials that can sustain a harsh thermal environment through improved oil cooling. In addition to modify the power output, piston cooling reduces the carbonization and pre-ignition caused by hot spots on sharp edges of the piston crown. In this study, in order to evaluate the piston cooling functionality and validate the numerical simulation, a test rig is designed and manufactured and it is equipped with glassy piston and cylinder to show the oil contact surface. Using this test rig, flow rate is measured in different oil pressures and temperatures. In addition, heat transfer coefficient for various engine speeds is determined. Also a numerical model has been developed using CFD approach for analysis of piston cooling oil jet and validated with existing experimental results at axisymmetric condition. Finally, oil contact area and heat transfer coefficient are predicted at the bottom of piston for real piston cooling jet conditions.

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