Latent Heat and Liquid Water Content (LWC) Sensor based on Transient Heat Flux Measurements

2018 ◽  
Author(s):  
Yiqiang Han ◽  
Jose Palacios
Keyword(s):  
Heat Flux ◽  
Water Content ◽  
Latent Heat ◽  
Liquid Water ◽  
Liquid Water Content ◽  
Flux Measurements ◽  
Transient Heat Flux

scholarly journals Changes in seasonal snow liquid water content during the snowmelt period in the Western Tianshan Mountains, China

2012 ◽  
Vol 6 (5) ◽  
pp. 4137-4169 ◽  
Author(s):  
H. Lu ◽  
W. S. Wei ◽  
M. Z. Liu ◽  
X. Han ◽  
W. Hong
Keyword(s):  
Heat Flux ◽  
Temporal Variation ◽  
Snow Cover ◽  
Water Content ◽  
Liquid Water ◽  
Sensible Heat Flux ◽  
Liquid Water Content ◽  
Snow Layer ◽  
Snowmelt Period ◽  
Western Tianshan

Abstract. Snow liquid water content is a very important parameter for snow hydrological processes, avalanche research and snow cover mapping by remote sensing. Snow liquid water content was measured with a portable instrument (Snow Fork) in the Tianshan Station for Snow Cover and Avalanche Research, Chinese Academy of Sciences during the snowmelt period in spring 2010. This study analyzed the temporal and spatial distribution of snow liquid water content in different weather conditions. The average liquid water content of snow in the whole layer exponentially increased and can be calculated using a regression function of prior moving average temperature. The proportion of net radiation, sensible heat flux and latent heat flux in total energy changed in different snowmelt period. During the pre-snowmelt period (0.3% ≤ Wvol < 1%), snow liquid water content and its temporal variation were relatively small, with liquid water accumulated in the coarse snow layer. During the mid-snowmelt period (1% ≤ Wvol < 2.5%), the variation was significant in the upper layer and decreased drastically during the snowfall and the following one to two days. Only the temporal variation decreased after rain or snow (ROS) events. During the late-snowmelt period (Wvol ≥ 2.5%), the distribution and variation of every snow layer showed a~uniform trend, and the effect of ROS events on liquid water content only occurred during rainfall and snowfall.

Fast-Response transient heat flux measurements in a plasma wind tunnel

2021 ◽  
Vol 173 ◽  
pp. 121234
Author(s):  
Byrenn Birch ◽  
David Buttsworth ◽  
Stefan Löhle ◽  
Fabian Hufgard
Keyword(s):  
Heat Flux ◽  
Wind Tunnel ◽  
Fast Response ◽  
Flux Measurements ◽  
Transient Heat Flux

scholarly journals Proof of Concept: Development of Snow Liquid Water Content Profiler Using CS650 Reflectometers at Caribou, ME, USA

Sensors ◽  
2017 ◽  
Vol 17 (3) ◽  
pp. 647 ◽  
Author(s):  
Carlos Pérez Díaz ◽  
Jonathan Muñoz ◽  
Tarendra Lakhankar ◽  
Reza Khanbilvardi ◽  
Peter Romanov
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Liquid Water Content ◽  
Concept Development ◽  
Proof Of Concept

An analog period method for gap‐filling of latent heat flux measurements

2021 ◽  
Author(s):  
Lucas Emilio B. Hoeltgebaum ◽  
Nelson Luís Dias ◽  
Marcelo Azevedo Costa
Keyword(s):  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Gap Filling ◽  
Flux Measurements

Field Measurement of the Liquid-Water Content of Snow

1981 ◽  
Vol 27 (95) ◽  
pp. 175-178 ◽  
Author(s):  
E. M. Morris
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Field Measurement ◽  
Solution Method ◽  
Liquid Water Content ◽  
Field Trials

Abstract Field trials show that the liquid-water content of snow can be determined simply and cheaply by a version of Bader’s solution method.

scholarly journals Snow dielectric properties: from DC to microwave X-band

1994 ◽  
Vol 19 ◽  
pp. 92-96 ◽  
Author(s):  
TH. Achammer ◽  
A. Denoth
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Water Content ◽  
Liquid Water ◽  
Liquid Water Content ◽  
Frequency Range ◽  
Snow Density ◽  
Cold Room ◽  
X Band ◽  
Grain Size And Shape

Broadband measurements of dielectric properties of natural snow samples near or at 0°C are reported. Measurement quantities are: dielectric permittivity, loss factor and complex propagation factor for electromagnetic waves. X-band measurements were made in a cold room in the laboratory; measurements at low and intermediate frequencies were carried out both in the field (Stubai Alps, 3300 m; Hafelekar near Innsbruck, 2100 m) and in the cold room. Results show that in the different frequency ranges the relative effect on snow dielectric properties of the parameters: density, grain-size and shape, liquid water content, shape and distribution of liquid inclusions and content of impurities, varies significantly. In the low-frequency range the influence of grain-size and shape and snow density dominates; in the medium-frequency range liquid water content and density are the dominant parameters. In the microwave X-band the influence of the amount, shape and distribution of liquid inclusions and snow density is more important than that of the remaining parameters.

Comparison of Water Thickness Profiles of Compressed PEMFC GDLs

2011 ◽  
Author(s):  
Pradyumna Challa ◽  
James Hinebaugh ◽  
A. Bazylak
Keyword(s):  
Water Content ◽  
Liquid Water ◽  
Water Distribution ◽  
Polymer Electrolyte Membrane ◽  
Water Injection ◽  
Liquid Water Content ◽  
Gas Diffusion ◽  
Injection Rate ◽  
Water Levels ◽  
Ex Situ

In this paper, through-plane liquid water distribution is analyzed for two polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layers (GDLs). The experiments were conducted in an ex situ flow field apparatus with 1 mm square channels at two distinct flow rates to mimic water production rates of 0.2 and 1.5 A/cm2 in a PEMFC. Synchrotron radiography, which involves high intensity monochromatic X-ray beams, was used to obtain images with a spatial and temporal resolution of 20–25 μm and 0.9 s, respectively. Freudenberg H2315 I6 exhibited significantly higher amounts of water than Toray TGP-H-090 at the instance of breakthrough, where breakthrough describes the event in which liquid water reaches the flow fields. While Freudenberg H2315 I6 exhibited a significant overall decrease in liquid water content throughout the GDL shortly after breakthrough, Toray TGP-H-090 appeared to retain breakthrough water-levels post-breakthrough. It was also observed that the amount of liquid water content in Toray TGP-H-090 (10%.wt PTFE) decreased significantly when the liquid water injection rate increased from 1 μL/min to 8 μL/min.

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