NUMERICAL SIMULATION OF AIR CURRENTS
AT THE INLET TO SLOT LEAKS OF VENTILATION SHELTERS
O. A. Averkova,
V. Yu. Zorya,
I. N. Logachev,
and K. I. Logachev
Translated from Novye Ogneupory, No. 5, pp. 31 – 36, May, 2010.
Original article submitted November 30, 2009.
A mathematical model, computational algorithm, and computer program for calculating the vortical air flows
in the slot leak of ventilation leaks equipped with thin baffle plates arranged randomly in space are developed
on the basis of the method of discrete vortices. The laws governing the variation in the characteristics of de
tached flows at the inlet to the slot leak of the baffle plate are discovered. The computed values are compared
to experimental data and calculations performed by means of other methods.
Keywords: method of discrete vortices, ventilation shelter, leak, baffle plate
Entry of air through a leak is among the factors that tend
to increase the power capacity of ventilation shelters. The
greater the area of the leak, the greater must be the power of
the ventilator motor responsible for creating the required rar-
efaction inside the shelter and, correspondingly, the speed of
air through the leak, thus hindering entrainment of dust into
the surrounding space. Because of technological reasons, it is
not always possible to achieve a completely airtight shelter.
For example, leaks are needed to allow for passage of a con
veyor belt. The question arises, how can the volume of air
that enters through a leak be reduced without reducing the
area of the leak. One way of achieving this is by increasing
the hydraulic resistance of the leak by equipping it with thin
baffle plates. Detachment of flow from the sharp corners of
the baffle plates promotes the appearance of vortical regions,
where the energy of the intake flow is lost. Moreover, the de
tached airstream reduces the area of the effective intake
through the leak. Thus, aerodynamic shielding of a leak by
means of thin baffle plates makes it possible to reduce harm
ful inflow of air through the use of the effect of airstream
separation. It is therefore of scientific and practical interest to
investigate detached air currents in the most widely em
ployed types of slot leaks of ventilation shelters [1, 2]
equipped with baffle plates.
Calculations of a detached current with the use of the
Zhukovskii method at the inlet to a slot leak provided with
baffle plates (Fig. 1) mounted in the wall of the casing were
performed in . The laws governing the variation of the
compression coefficient across the slot with different ratios
of the length of the baffle plate to the width of the slot were
also determined in this study. It was suggested that the flow
is potential and that the velocity is constant on the free flow
line. The flow boundary has a simplified form (cf. Fig. 1a )
and, correspondingly, the geometry of the shelter is not taken
into account. Significant difficulties arises when attempting
to solve the problem for several types of shelters. It is not
possible to calculate the flow between the free current line
and the baffle plate within the framework of this model.
Separation of flow from the edges of a round tube with
flanges (Fig. 2) was studied in  on the basis of the method
of discrete annular vortices. The influence of the baffle plate
and the inflow airstream outflowing from the sides of the
baffle plate on the Coriolis coefficient at the inlet opening of
Refractories and Industrial Ceramics Vol. 51, No. 3, 2010
1083-4877/10/5103-0177 © 2010 Springer Science+Business Media, Inc.
Shukhov State Technological University, Belgorod, Russia.
Fig. 1. Calculation of potential flow at inlet to a slot leak. a) bound
aries of flow region; b) profile of horizontal component of velocity
and current line.