The enhancement of spray cooling at very high initial temperature by using dextrose added water

2020 ◽  
Vol 150 ◽  
pp. 119311 ◽  
Author(s):  
L. Das ◽  
A.R. Pati ◽  
Anita Panda ◽  
B. Munshi ◽  
D.K. Sahoo ◽  
...  
Keyword(s):  
Initial Temperature ◽  
Spray Cooling ◽  
Added Water ◽  
Very High ◽  
High Initial Temperature

The SDS and steel surface interaction behaviour in case of high mass flux spray cooling from very high temperature

2019 ◽  
Vol 157 ◽  
pp. 508-517
Author(s):  
Lily Das ◽  
B. Swain ◽  
B. Munshi ◽  
S.S. Mohapatra ◽  
A. Behera
Keyword(s):  
High Temperature ◽  
Mass Flux ◽  
Steel Surface ◽  
Spray Cooling ◽  
Surface Interaction ◽  
High Mass ◽  
Very High

Synthesis of a Novel Intumescent Flame Retardant Oligomer and its Application in ABS Copolymer

2011 ◽  
Vol 391-392 ◽  
pp. 204-208
Author(s):  
Xiao Ping Hu ◽  
Yu Yang Guo ◽  
Quan Min Xu ◽  
Hui Min Heng ◽  
Liang Jun Li
Keyword(s):  
Flame Retardant ◽  
Initial Temperature ◽  
Oxygen Index ◽  
Intumescent Flame Retardant ◽  
Char Residue ◽  
Mass Ratio ◽  
Limiting Oxygen Index ◽  
Ul 94 ◽  
Combustion Behaviors ◽  
High Initial Temperature

A novel intumescent flame retardant oligomer containing phosphorous-nitrogen structure (PSPTR) was synthesized and characterized by Fourier Transform Infrared (FTIR) and Mass Spectrometry (MS). The thermal behavior of PSPTR was investigated by thermogravimetric analysis (TGA). The TGA data shows that PSPTR has a high initial temperature of thermal degradation and a high char residue of 41.18wt% at 700 . A novel intumescent flame retardant (IFR) system, which is composed of PSPTR and novolac phenol (NP), was used to impart flame retardancy of ABS. The combustion behaviors of the ABS/IFR composites were investigated by Limiting Oxygen Index (LOI) and UL-94 tests. When the content of IFR (PSPTR:NP=1:1 mass ratio) is 30 wt%, the LOI value of ABS/IFR reaches 28.2, and the vertical burning test reaches UL-94 V-1 rating.

Temperature Variations in Drilling of CFRP/Aluminum and CFRP/Titanium Stacks

2016 ◽  
Vol 10 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Masahiko Sato ◽  
◽  
Hisataka Tanaka ◽  
Kanae Yamamoto ◽  
Keyword(s):  
Optical Fiber ◽  
Thermal Damage ◽  
Initial Temperature ◽  
Bottom Surface ◽  
Radiation Pyrometer ◽  
Temperature Variations ◽  
Fiber Reinforced Plastic ◽  
Reinforced Plastic ◽  
Infrared Rays ◽  
Very High

This paper describes the temperature variations observed in the drilling of carbon fiber-reinforced plastic (CFRP)/Al, CFRP/Ti, Al/CFRP, and Ti/CFRP stacks. An infrared radiation pyrometer equipped with an optical fiber was used to measure the temperature. The optical fiber, inserted into the oil hole of an internal-coolant carbide drill, registered the infrared rays radiating from the bottom surfaces of the drilled holes. In drilling the CFRP/Ti stack, the temperature was ∼95°C in the CFRP layer. As the drill progressed into the Ti layer, the temperature increased to a very high value of 745°C at the bore exit. In the Ti/CFRP stack, meanwhile, the initial temperature was ∼170°C and increased to 695°C at the Ti/CFRP interface. Severe thermal damage, including fiber/resin pullout and matrix degradation, was caused by the heat at the bottom surface of the drilled hole in the Ti/CFRP stack. Along the edge of the entry point in the CFRP, the CFRP matrix was degraded by the heat. In drilling the CFRP/Al stack, the temperature in the Al layer was 200°C; little thermal damage was observed.

Characteristics of Wetting Temperature and Maximum Heat Flux During Spray Cooling of Hot Surface

2010 ◽  
Author(s):  
Yuichi Mitsutake ◽  
Masanori Monde
Keyword(s):  
Heat Flux ◽  
Mass Flux ◽  
Initial Temperature ◽  
Thermal Inertia ◽  
Spray Cooling ◽  
Inverse Heat Conduction ◽  
Quenching Temperature ◽  
Maximum Heat ◽  
Maximum Heat Flux ◽  
Hot Surface

An experimental investigation has been done to elucidate the effects of mass flux G, degree of subcooling ΔTsub and initial solid temperature Tb0 on transient spray cooling of a downward facing φ89 mm hot block surface. The spray impact diameter was adjusted to φ110mm and φ36mm which simulate uniform and non-uniform spray cooling of the surface. The block made of copper, brass and carbon steel at an initial temperature of 200–500 °C was cooled with subcooled water and ethanol spray. The subcooling was from 10 to 80 K and the mass flux was from 1 to 72 kg/m2s. Surface temperature and surface heat flux were evaluated with an axisymmetric 2D inverse heat conduction analysis. A transient transition regime was characterized with a wetting temperature and a quenching temperature. The wetting and quenching temperatures were correlated fairly with GΔTsub. Effects of G, ΔTsub, Tb0 and a thermal inertia of the solid (ρcλ)s on a maximum heat flux are evaluated.

scholarly journals Effect of Initial Temperature on the Microstructure and Properties of Stellite-6/Inconel 718 Functional Gradient Materials Formed by Laser Metal Deposition

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3609
Author(s):  
Jun Yao ◽  
Bo Xin ◽  
Yadong Gong ◽  
Guang Cheng
Keyword(s):  
Inconel 718 ◽  
Room Temperature ◽  
Initial Temperature ◽  
Gradient Material ◽  
Laser Metal Deposition ◽  
Functional Gradient ◽  
Stellite 6 ◽  
Melt Pool ◽  
Functional Gradient Material ◽  
High Initial Temperature

Stelite-6/Inconel 718 functionally gradient materials (FGM) is a heat-resisting functional gradient material with excellent strength performance under ultra-high temperatures (650–1100 °C) and, thus, has potential application in aeronautic and aerospace engineering such as engine turbine blade. To investigate the effect of initial temperature on the microstructure and properties of laser metal deposition (LMD) functional gradient material (FGM), this paper uses the LMD technique to form Stelite-6/Inconel 718 FGM at two different initial temperatures: room temperature and preheating (300 °C). Analysis of the internal residual stress distribution, elemental distribution, microstructure, tensile properties, and microhardness of 100% Stelite-6 to 100% Inconel 718 FGM formed at different initial temperatures in a 10% gradient. The experimental results prove that the high initial temperature effectively improves the uneven distribution of internal residual stresses. Preheating slows down the solidification time of the melt pool and facilitates the escape of gases and the homogeneous diffusion of elements in the melt pool. In addition, preheating reduces the bonding area between the gradient layers, enhancing the metallurgical bonding properties between the layers and improving the tensile properties. Compared with Stellite-6/Inconel 718 FGM formed at room temperature, the mean yield strength, mean tensile strength, and mean elongation of Stellite-6/Inconel 718 FGM formed at 300 °C are increased by 65.1 Mpa, 97 MPa, and 5.2%. However, the high initial temperature will affect the hardness of the material. The average hardness of Stellite-6/Inconel 718 FGM formed at 300 °C is 26.9 HV (Vickers hardness) lower than that of Stellite-6/Inconel 718 FGM formed at 20 °C.

scholarly journals A thermal parametric study of non-evaporative spray cooling process

2018 ◽  
Vol 240 ◽  
pp. 01030
Author(s):  
Abdessalam Otmani ◽  
Hocine Mzad ◽  
Kamel Bey
Keyword(s):  
Heat Transfer ◽  
Phase Change ◽  
Spray Cooling ◽  
Comsol Multiphysics ◽  
Cooling Process ◽  
Height Range ◽  
Hydrodynamic Parameters ◽  
Present Simulation ◽  
Very High ◽  
Water Spray Cooling

Ordinary water spray cooling is connected with very high temperatures where heat transfer during evaporation plays a key role. However, during cooling without phase change, the behaviour of the spray cooling parameters is rarely considered. The purpose of this paper is to study the influence of spray hydrodynamic parameters on heat transfer without liquid phase change during the cooling of an aluminium 3003-H18 plate at a temperature of 92 °C. First of all, the flow rate was varied from 0.497 up to 1 l/min. Then, the inlet pressure varied from 0.7 to 2.1 bars. The influence of nozzle-to-target distance is also tested since the simulations were carried out in a wide height range, from 100 mm to 505 mm. The present simulation was achieved using the version 5.2 of COMSOL Multiphysics code.

scholarly journals A probabilistic model for estimating ocean-spray distribution in extreme tropical cyclone winds

MAUSAM ◽  
2021 ◽  
Vol 48 (4) ◽  
pp. 489-498
Author(s):  
JAMES LIGHT HILL
Keyword(s):  
Tropical Cyclone ◽  
Initial Temperature ◽  
Mechanical Energy ◽  
Spray Cooling ◽  
Wind Speeds ◽  
Extreme Wind ◽  
Future Global Warming ◽  
Ocean Spray ◽  
Spray Distribution ◽  
Extreme Wind Speeds

ABSTRACT. Serious gaps in knowledge about ocean spray at wind speeds over 28 m/s remain difficult to fill by observation or experiment; yet refined study of the thermodynamics of Tropical Cyclones (including typhoons and hurricanes) requires assessment of the hypothesis that ‘spray cooling’ at extreme wind speeds may act to reduce (i) the initial temperature of saturated air rising in the eyewall and so also (ii) the input of mechanical energy into the airflow as a whole. Such progressive reductions at higher speeds could, for example, make any possible influence, of future global warming on Tropical Cyclone intensification largely se1f-limiting. In order to help in extrapolation of knowledge on ocean spray to extreme wind speeds, a probabilistic analysis is introduced which allows for the effects of gusts, gravity and evaporation on droplet distributions yet all other respect is as simple as possible. Preliminary indications from this simplified analysis appear to confirm the potential importance of spray cooling.    

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