Thermal structure of an in situ gas combustion wave

1985 ◽  
Vol 21 (2) ◽  
pp. 146-151 ◽  
Author(s):  
S. I. Potytnyakov ◽  
V. S. Babkin ◽  
Yu. M. Laevskii ◽  
V. I. Drobyshevich
Keyword(s):  
Combustion Wave ◽  
Thermal Structure ◽  
Gas Combustion

Ignition of a Filtration Gas Combustion Wave by a Heated Region of a Porous Medium

2019 ◽  
Vol 55 (6) ◽  
pp. 654-660
Author(s):  
E. V. Manzhos ◽  
N. A. Kakutkina ◽  
A. A. Korzhavin ◽  
A. D. Rychkov ◽  
P. K. Senachin
Keyword(s):  
Porous Medium ◽  
Combustion Wave ◽  
Heated Region ◽  
Gas Combustion

scholarly journals Upper-Ocean Thermal Structure and the Western North Pacific Category 5 Typhoons. Part II: Dependence on Translation Speed

2009 ◽  
Vol 137 (11) ◽  
pp. 3744-3757 ◽  
Author(s):  
I-I. Lin ◽  
Iam-Fei Pun ◽  
Chun-Chieh Wu
Keyword(s):  
Mixed Layer ◽  
North Pacific ◽  
Western North Pacific ◽  
Thermal Structure ◽  
Subsurface Layer ◽  
Heat Content ◽  
Correlation Coefficients ◽  
Upper Ocean ◽  
Translation Speed

Abstract Using new in situ ocean subsurface observations from the Argo floats, best-track typhoon data from the U.S. Joint Typhoon Warning Center, an ocean mixed layer model, and other supporting datasets, this work systematically explores the interrelationships between translation speed, the ocean’s subsurface condition [characterized by the depth of the 26°C isotherm (D26) and upper-ocean heat content (UOHC)], a cyclone’s self-induced ocean cooling negative feedback, and air–sea enthalpy fluxes for the intensification of the western North Pacific category 5 typhoons. Based on a 10-yr analysis, it is found that for intensification to category 5, in addition to the warm sea surface temperature generally around 29°C, the required subsurface D26 and UOHC depend greatly on a cyclone’s translation speed. It is observed that even over a relatively shallow subsurface warm layer of D26 ∼ 60–70 m and UOHC ∼ 65–70 kJ cm−2, it is still possible to have a sufficient enthalpy flux to intensify the storm to category 5, provided that the storm can be fast moving (typically Uh ∼ 7–8 m s−1). On the contrary, a much deeper subsurface layer is needed for slow-moving typhoons. For example at Uh ∼ 2–3 m s−1, D26 and UOHC are typically ∼115–140 m and ∼115–125 kJ cm−2, respectively. A new concept named the affordable minimum translation speed Uh_min is proposed. This is the minimum required speed a storm needs to travel for its intensification to category 5, given the observed D26 and UOHC. Using more than 3000 Argo in situ profiles, a series of mixed layer numerical experiments are conducted to quantify the relationship between D26, UOHC, and Uh_min. Clear negative linear relationships with correlation coefficients R = −0.87 (−0.71) are obtained as Uh_min = −0.065 × D26 + 11.1, and Uh_min = −0.05 × UOHC + 9.4, respectively. These relationships can thus be used as a guide to predict the minimum speed a storm has to travel at for intensification to category 5, given the observed D26 and UOHC.

Catalytic Drying of Digested Sludge

2004 ◽  
Vol 2 (1) ◽  
Author(s):  
Jamal Chaouki
Keyword(s):  
Combustion Chamber ◽  
Spouted Bed ◽  
Digested Sludge ◽  
Gas Combustion ◽  
Fluidized Bed Dryer ◽  
Oxidation Of Hydrocarbons ◽  
Natural Gas Combustion ◽  
Set Up ◽  
Main Components

Recently, we patented an efficient process for the drying of digested sludge with zero liquid emission. The main components of this drying system are a conical spouted bed dryer and a natural gas combustion chamber that burns the Volatile Organic Compounds (VOC) in the drying gases. The proposed integrated spouted bed drying process is simple and safe. It is also robust and easy to maintain since there is no moving mechanical part in the set-up. Although the system is quite thermally efficient, the operating and the investment costs are still relatively high. In order to avoid the combustion chamber and its accessories operating at high temperature and to reduce the energy consumption, a catalytic fluidized bed dryer may replace these units. It is proposed, then, to produce in situ the energy for the drying by catalytic oxidation of hydrocarbons and to destroy catalytically the VOCs generated by the drying. The purpose of this paper is to show the feasibility of this new process, called the catalytic drying of digested sludge. Based on the experimental work, advantages and limitations of this process are also discussed.

Flashback Detection Sensor for Hydrogen Augmented Natural Gas Combustion

2007 ◽  
Author(s):  
Jimmy D. Thornton ◽  
B. T. Chorpening ◽  
Todd G. Sidwell ◽  
Peter A. Strakey ◽  
E. D. Huckaby ◽  
...  
Keyword(s):  
Natural Gas ◽  
Hydrogen Combustion ◽  
Flame Speed ◽  
In Situ Monitoring ◽  
Ion Concentration ◽  
Pure Hydrogen ◽  
Gas Combustion ◽  
Combustion Systems ◽  
Natural Gas Combustion

The use of hydrogen augmented fuel is being investigated by various researchers as a method to extend the lean operating limit, and potentially reduce thermal NOx formation in natural gas fired lean premixed (LPM) combustion systems. The resulting increase in flame speed during hydrogen augmentation, however, increases the propensity for flashback in LPM systems. Real-time in-situ monitoring of flashback is important for the development of control strategies for use of hydrogen augmented fuel in state-of-the-art combustion systems, and for the development of advanced hydrogen combustion systems. The National Energy Technology Laboratory (NETL) and Woodward are developing a combustion control and diagnostics sensor (CCADS), which has already been demonstrated as a useful sensor for in-situ monitoring of natural gas combustion, including detection of important combustion events such as flashback and lean blowoff. Since CCADS is a flame ionization sensor technique, the low ion concentration produced in pure hydrogen combustion raises concerns of whether CCADS can be used to monitor flashback in hydrogen augmented combustion. This paper discusses CCADS tests conducted at 0.2-0.6 MPa (2–6 atm), demonstrating flashback detection with fuel compositions up to 80% hydrogen (by volume) mixed with natural gas. NETL’s Simulation Validation (SimVal) combustor offers full optical access to pressurized combustion during these tests. The CCADS data and high-speed video show the reaction zone moves upstream into the nozzle as the hydrogen fuel concentration increases, as is expected with the increased flame speed of the mixture. The CCADS data and video also demonstrate the opportunity for using CCADS to provide the necessary in-situ monitor to control flashback and lean blowoff in hydrogen augmented combustion applications.

Atmospheric Entry Probes for in situ Exploration of the Ice Giant Planets

2021 ◽  
Author(s):  
David H. Atkinson ◽  
Olivier J. Mousis ◽  
Mark Hofstadter ◽  
Sushil K. Atreya
Keyword(s):  
Remote Sensing ◽  
Solar System ◽  
Noble Gas ◽  
Thermal Structure ◽  
Giant Planets ◽  
Atmospheric Entry ◽  
Cloud Properties ◽  
Entry Probe ◽  
Galileo Probe

<p>Understanding the formation and evolution of the solar system and the formation of the giant planets is constrained by inherent limitations in the capabilities of remote sensing. In situ exploration of planetary atmospheres provides key measurements not possible from remote observations, remarkably demonstrated at Jupiter by the Galileo probe, where key measurements included the determination of noble gas abundances and the precise measurement of the Jupiter helium mixing ratio. In this paper, we describe the primary scientific goals to be addressed by future in situ exploration of the ice giants Uranus and Neptune, placing in situ explorations of the gas giants, including the Galileo probe and a future Saturn probe, into a broader solar system context. An ice giant atmospheric entry probe reaching 10 bars would provide insight into both the formation history of the solar system and the giant planets, and the structure and composition of, and physical processes at play within ice giant atmospheres. An entry probe as an element of a future ice giant flagship mission would descend under parachute to measure the abundances and isotopic ratios of the noble gases, D/H in H<sub>2</sub> and <sup>13</sup>C/<sup>12</sup>C, and the thermal structure and dynamics from the upper atmosphere down to the deepest region from which the probe is able to return data, perhaps 10-20 bars or more. Probe data would be returned to Earth using a Carrier Relay Spacecraft as a relay station. The relay spacecraft, particularly if it is an orbiter with a suite of remote sensing instruments, can significantly enhance the science return from the probe; remote sensing provides the global context from which to understand the probe's local measurements of weather and cloud properties. One or more small atmospheric probes could represent a significant ESA contribution to a future NASA New Frontiers or Flagship Ice Giant mission.</p> <p> </p>

scholarly journals A Method to Estimate Three-Dimensional Thermal Structure from Satellite Altimetry Data

2009 ◽  
Vol 26 (12) ◽  
pp. 2655-2664 ◽  
Author(s):  
Akiko Takano ◽  
Hidekatsu Yamazaki ◽  
Takeyoshi Nagai ◽  
Osamu Honda
Keyword(s):  
Satellite Altimetry ◽  
Thermal Structure ◽  
Three Dimensional ◽  
Empirical Method ◽  
Altimetry Data ◽  
Spatiotemporal Mapping ◽  
Strong Linear Correlation ◽  
Globally Distributed ◽  
Satellite Altimetry Data

Abstract A new empirical method to estimate mesoscale three-dimensional oceanic thermal structures from near-real-time satellite altimetry data is presented. The method uses a two-layer model with a novel set of empirical parameters for stratification. Empirical parameters, which are calculated from altimetry data and in situ temperature and salinity profiles obtained from globally distributed Argo floats, allowed for significant increases in the spatiotemporal mapping of mesoscale temperature distributions. The accuracy of the method was validated by comparing the estimated isothermal depths with in situ temperature data. Three case studies in different regions and seasons showed excellent agreement, with a strong linear correlation between the estimated and observed isothermal depths. The authors present the details of the method, discuss its limitations, and demonstrate the ecological relevance of the method for fisheries management by successfully predicting pelagic fish distributions.

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