Abstract
An analytical investigation into compressible gas flow with slight rarefactions through the insect trachea and tracheoles during the closed spiracle phase is undertaken, and a complete set of asymptotic analytical solutions is presented. We first obtain estimates of the Reynolds and Mach numbers at the channel terminal ends where the tracheoles directly deliver respiratory gases to the cells, by comparing the magnitude of the different forces in the compressible gas flow. The 2D Navier–Stokes equations with a slip boundary condition are used to investigate compressibility and rarefied effects in the trachea and tracheoles. Expressions for the velocity components, pressure gradients and net flow inside the trachea are then presented. Numerical simulations of the tracheal compressible flow are performed to validate the analytical results from this study. This work extends previous work of Arkilic et al. (J Microelectromech Syst 6(2):167–178, 1997) on compressible flows through a microchannel. Novel devices for microfluidic compressible flow transport may be invented from results obtained in this study.
Similar content being viewed by others
Notes
We define the aspect ratio as the ratio of the longest side to the shortest side, i.e. we define the aspect ratio as the length (L) to breadth (B) ratio (\(\delta ^{-1} = L/B \gg 1\)).
The \(\delta ^0\)-term for \(\tilde{v}\) is equal to zero and is not included in the expansion of \(\tilde{v}\) because it is clear from the non-dimensional continuity equation (Eq. 2.8) that the highest order \(\tilde{v}\) term that is required to satisfy the differential continuity equation is \(\mathcal {O} (\delta )\).
References
Aboelkassem Y, Staples AE (2012) Flow transport in a microchannel induced by moving wall contractions: a novel micropumping mechanism. Acta Mech 223:463–480
Aboelkassem Y, Staples AE (2013) Selective pumping in a network: insect-style microscale flow transport. Bioinspir Biomim 8:026004
Arkilic EB, Schmidt MA, Kenneth SB (1997) Gaseous slip flow in long microchannels. J Microelectromech Syst 6(2):167–178
Beskok A, Karniadakis G (1993) Simulation of heat and momentum transfer in micro-geometries. AIAA Paper, 93-3269
Cai C, Boyd I, Fan J, Candler GV (2000) Direct simulation methods for low-speed microchannel flows. J Thermophys Heat Transf 14:368–378
Cai C, Liu DD, Boyd ID (2007) Compressible gas flow inside a two dimensional uniform microchannel. AIAA Aerospace Sciences Meeting, Reno, Nevada
Duncan FD, Byrne MJ (2002) Respiratory airflow in a wingless beetle. J Exp Biol 205:2489–2497
Glowinski R, Lichnewsky A (1990) Computing methods in applied sciences and engineering. SIAM, Philadelphia, pp 162–164
Gullan PJ, Cranston PS (2014) The insects: an outline of entomology, 5th edn. Wiley, New York
Hetz SK, Wasserthal LT, Hermann S, Kaden H, Oelbner W (1994) Direct oxygen measurements in the tracheal system of lepidopterous pupae using miniaturized amperometric sensors. Bioelectrochem Bioenerg 33(2):165–170
Li M, Brasseur JG (1993) Non-steady peristaltic transport in finite-length tubes. J Fluid Mech 248:129–151
Lord R (1977) Tangential momentum accommodation coefficients of rare gases on polycrystalline metal surfaces. In: Potter J (ed) Rarefied gas dynamics. American Institute of Aeronautics and Astronautics, New York
Massey B (1989) Mechanics of fluids, 6th edn. Van Nostrand, London
Nation JL (2002) Insect physiology and biochemistry. CRC Press, Boca Raton, pp 327–347
Oran ES, Oh CK, Cybyk BZ (1998) Direct simulation Monte Carlo: recent advances and applications. Annu Rev Fluid Mech 30:403–441
Piekos E, Breuer K (1995) DSMC modeling of micromechanical devices. AIAA Paper, 95-2089
Pong K, Ho C, Liu J, Tai Y (1994) Non-linear pressure distribution in uniform microchannels. In Application of microfabrication to fluid mechanics, ASME Winter Annual Meeting, Chicago, IL, pp 51–56
Schmitz A, Perry SF (1999) Stereological determination of tracheal volume and diffusing capacity of the tracheal walls in the stick insect Carausius morosus (Phasmatodea, Lonchodidae). J Physiol Biochem Zool 72(2):205–218
Simelane SM, Abelman S, Duncan FD (2016) Gas exchange models for a flexible tracheal system. J Acta Biotheor 64(2):161–196
Socha JJ, Lee WK, Harrison JF, Waters JS, Fezzaa K, Westneat MW (2008) Correlated patterns of tracheal compression and convective gas exchange in a carabid beetle. J Exp Biol 211:3409–3420
Socha JJ, Forster TD, Greenlee KJ (2010) Issues of convection in insect respiration: insights from synchrotron X-ray imaging and beyond. Respir Physiol Neurobiol 173:65–73
Wang X, Cheng C, Wang S, Liu S (2009) Electroosmotic pumps and their applications in microfluidic systems. Microfluid Nanofluidics 6(2):145
Wasserthal LT (2014) Periodic heartbeat reversals cause cardiogenic inspiration and expiration with coupled spiracle leakage in resting bowflies, Calliphora vicina. J Exp Biol 217:1543–1554
White FM (1991) Viscous fluid flow. McGraw-Hill, Boston
Withers CP (1992) Comparative animal physiology. Sanders College Publishing, Orlando
Wolfram Research, Inc (2012) Mathematica, Version 9.0, Champaign, IL
Xu K, Li Z (2004) Microchannel flow in the slip regime: gas-kinetic BGK-Burnett solutions. J Fluid Mech 513:87–110
Zohar Y, Lee SY, Lee WY, Jiang L, Tong P (2004) Subsonic gas flow in a straight and uniform microchannel. J Fluid Mech 472:125–151
Acknowledgements
Professors Shirley Abelman and Frances Duncan thank the NRF South Africa for financial support. The reviewers are thanked for their careful reading of our manuscript. Their useful comments have resulted in an improved manuscript.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interests
The authors declare that there is no conflict of interests regarding the publication of this paper.
Additional information
This document is a collaborative effort.
Rights and permissions
About this article
Cite this article
Simelane, S.M., Abelman, S. & Duncan, F.D. Microscale Gaseous Slip Flow in the Insect Trachea and Tracheoles. Acta Biotheor 65, 211–231 (2017). https://doi.org/10.1007/s10441-017-9312-9
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10441-017-9312-9