An analytical study of air circulation in caves

Cigna, Arrigo A.

doi:10.5038/1827-806x.3.1.3

Cited by 53 publications

(53 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The frequencies of airflow oscillations from 0.3 to 40 mHz are roughly in the range reported by Plummer (1969). Further details on cave airflow oscillations can be found in Faust (1947), Cigna (1968), or Faimon et al (2012.…”

Section: Discussionsupporting

confidence: 60%

See 1 more Smart Citation

Variances in airflows during different ventilation modes in a dynamic U-shaped cave

Faimon¹,

Lang²

2013

IJS

View full text Add to dashboard Cite

Airflow dynamics were studied in Císařská Cave (Moravian Karst, Czech Republic) under different seasonal conditions. The dependence of airflows on the difference between external and cave temperatures is nonlinear and roughly obeys the Darcy-Weisbach equation. The upward airflows were found to be systematically higher than the downward airflows under comparable driving forces. The principle reason is nonlinearity between air temperature and air density. U-shaped cave geometry magnifies this effect by feedback between external temperature and airflow driving forces. Whereas this feedback is positive during the upward airflow ventilation mode, it is negative during the downward airflow mode. To discuss the behavior in detail, a simplified model based on balancing the masses of two equivalent air columns of different temperatures and densities is proposed. The results contribute to a better understanding of cave microclimate evolution, cave CO2 dynamics, and speleothem growth

show abstract

Section: Discussionsupporting

confidence: 60%

“…In principle, cave airflows can be produced (1) dynamically, by moving fluids (Cigna, 1968), or (2) statically, by pressure differences derived from different air densities (Bögli, 1978;de Freitas et al, 1982). We have focused on the second mechanism because this one operates in the cave of interest.…”

Section: Introductionmentioning

confidence: 99%

Variances in airflows during different ventilation modes in a dynamic U-shaped cave

Faimon¹,

Lang²

2013

IJS

View full text Add to dashboard Cite

show abstract

“…All the entrances/ openings in distinct altitudes are responsible for the dynamic behavior of cave air circulation. A theoretical background on cave air circulation was given by Cigna (1968) and Wigley & Brown (1971). Several studies on artificial systems (e.g., Richon et al, 2005) can also be useful for the better understanding natural systems.…”

Section: Site Of Studymentioning

confidence: 99%

The impact of door opening on CO2 levels: A case study from the Balcarka Cave (Moravian Karst, Czech Republic)

Lang¹,

Faimon²,

Kejíková³

2017

IJS

View full text Add to dashboard Cite

Abstract:The impact of door opening on cave carbon dioxide (CO 2 ) levels was studied in the Entrance Chamber and the Gallery Chamber of the Balcarka Cave (Moravian Karst, Czech Republic). The effect of door opening differed with cave ventilation modes. Under upward airflow mode, the cave door opening led to the increase of output advective CO 2 fluxes from the cave and to the decrease of CO 2 levels. This effect was evident especially in the Entrance Chamber near the cave entrance and then suppressed in the Gallery Chamber situated deeper in the cave. Under the downward airflow mode, the cave door opening changed airflow paths and main CO 2 sources/fluxes. This resulted in the increase of CO 2 level in the Entrance Chamber while the levels in the Gallery Chamber decrease. Modeling indicates that the increase could be result of input advective CO 2 fluxes from epikarst (up to 5.9 × 10 -2 mol s -1 ). To reduce the impact on cave microclimate, a careful control of the visiting regime without overlapping of individual doors' openings is recommended. cave chamber, CO 2 levels, cave ventilation, door opening, advective CO 2 flux

show abstract

“…Since density is particularly a function of temperature, cave airflows are mostly related to the temperature difference DT = T exterior -T cave (where T exterior is external air temperature and T cave is cave air temperature [°C]) (de Freitas et al, 1982;Baker & Genty, 1998;Pflitsch & Piasecki, 2003;Russell & MacLean, 2008;Kowalczk & Froelich, 2010;Faimon et al, 2012b). A theoretical background on cave air circulation was given by Cigna (1968) and Wigley & Brown (1971). Based on their geometry, caves may be sorted into two extreme numbers.…”

Section: Introductionmentioning

confidence: 99%

The relationship between carbon dioxide concentration and visitor numbers in the homothermic zone of the Balcarka Cave (Moravian Karst) during a period of limited ventilation

Lang¹,

Faimon²,

Ek³

2015

IJS

View full text Add to dashboard Cite

An analytical study of air circulation in caves

Cited by 53 publications

References 0 publications

Variances in airflows during different ventilation modes in a dynamic U-shaped cave

Variances in airflows during different ventilation modes in a dynamic U-shaped cave

The impact of door opening on CO2 levels: A case study from the Balcarka Cave (Moravian Karst, Czech Republic)

The relationship between carbon dioxide concentration and visitor numbers in the homothermic zone of the Balcarka Cave (Moravian Karst) during a period of limited ventilation

Contact Info

Product

Resources

About