INVESTIGATION OF THE PROCESS OF OUTFLOW OF BOILING WATER THROUGH ORIFICES AND CYLINDRICAL NOZZLES

A. A. GURCHENOK

Presented by Professor G. I. FUKS

The process of outflow of boiling water has long been studied. However, to this day some aspects of this process remain unclear, and existing ideas about the nature of the vapor-formation process during outflow are contradictory.

In the present work, the discharge capacity of cylindrical nozzles of various lengths has been determined, with measurement of the pressure along the length of the nozzles. On the basis of the experimental results, considerations are expressed concerning the flow pattern, and a method is given for calculating the discharge capacity of orifices and cylindrical nozzles of various lengths for boiling water.

Notation adopted:

$d$ — nozzle diameter, mm,
$f$ — cross-sectional area, cm²,
$G$ — flow rate, kg,
$g$ — acceleration due to gravity, m/sec²,
$i$ — enthalpy, kcal/kg,
$x$ — steam dryness fraction, kg/kg,
$p$ — pressure, ata, kg/cm²,
$l$ — nozzle length, mm,
$v$ — specific volume, m³/kg,
$w$ — velocity, m/sec,
$\mu$ — discharge coefficient,
$\varphi$ — velocity coefficient,
$\varepsilon$ — jet contraction coefficient.

I. Literature Data

Theoretical investigations of the process of boiling-water outflow were first carried out by Zeiner [1], Lorenz [2], Rateau [3], and Fliegner [4]. They considered the process of boiling-water outflow as a process of adiabatic expansion (Fig. 1).

The authors apply the formulas of thermodynamics and obtain that the outflow velocity will be equal to:

\[ w_1 = 91.5 \sqrt{i'_1 - i_2}\ \text{m/sec}, \tag{1} \]

Fig. 1.

where

\[ i_3 = i_2 + x \cdot r \ \text{kcal/kg}. \tag{2} \]

Then, from the value of the velocity, the discharge capacity is determined:

\[ G_{\text{theor.}} = f \frac{w}{v_{\text{sm}}} \ \text{kg/sec}, \tag{3} \]

where

\[ v_{\text{sm}} = v' + x\left(v'' - v'\right) \ \text{m}^3/\text{kg}. \tag{4} \]

Different authors take different values for the pressure at the end of expansion. Zeiner and Lorenz assumed that complete expansion to the back pressure occurs; Rateau and Fliegner supposed that a critical pressure is established, the magnitude of which should be determined from the condition of obtaining the maximum discharge capacity. An example of such a calculation is given in Table 1.

Table 1

From Table 1 it is evident that the pressure of 5.4 ata should be taken as the critical pressure.

Experimental investigation of the outflow process, carried out by Bonin and Pulin [5] and by Adam [6], showed that the discharge capacity of nozzles with boiling water proves to be several times greater than the maximum capacity determined theoretically, Table 2.

The indicated discrepancy between the results of theoretical calculations and experimental data showed that, in order to determine the discharge capac-

Table 2

the capacity of nozzles with boiling water, the formulas of adiabatic expansion cannot be applied. At a later time, Dalin [7] and Yakadin [8] also used formulas of adiabatic expansion to calculate the capacity of nozzles and orifices with boiling water.

According to Dalin’s formula, by which the flow rate is equal to

\[ G_{k.v} = \frac{ 1.26 \mu d^2 \sqrt{(p_1 - p_2)\dfrac{v_1 + v_{c.m}}{2}} }{ v_{c.m} } \ \text{kg/hour} \tag{5} \]

the results are smaller than those obtained from the above theoretical calculations by a factor of \(\sqrt{2}\).

Yakadin recommends separately calculating the area for the steam and the liquid and taking the flow cross section as equal to the sum of these areas:

\[ f = f_p + f_l . \tag{6} \]

The amount of steam formed in this case is determined by him from the magnitude of the pressure loss due to friction, \(\Delta p_{tr}\), and the liquid flow rate from the total pressure difference \(p_1 - p_2\). It follows that beyond the nozzle, in one and the same section, two pressures must exist: for the steam \(p_p = p_1 - \Delta p_{tr}\) kg/cm² and for the liquid part \(p_l = p_2\) kg/cm².

In reality this is not observed, which points to the artificiality of the formula. It follows from it that an additional area is necessary for the passage of steam during outflow through an orifice, whereas this is not required.

Other calculation methods have also become established in practice. Thus, in calculating condensate traps, Stroganov’s formula [9] is used, by which the flow rate of cooled condensate is determined:

\[ G_k = 32 d^2 \sqrt{(p_1 - p_2)} \ \text{kg/hour} \tag{7} \]

According to MEI data [10], the flow rate of boiling water through orifices is equal to 0.25 of the flow rate of cold water, i.e.,

\[ G_{k.v} = 0.25 G_{x.v} = 5.65 d^2 \sqrt{(p_1 - p_2)} \ \text{kg/hour}, \tag{8} \]

where

\[ G_{x.v} = 22.6 d^2 \sqrt{(p_1 - p_2)} \ \text{kg/hour} \tag{9} \]

Experiments on the outflow of boiling water through orifices do not confirm relation (8). According to experimental data, the flow rate of boiling water through orifices remains almost equal to the flow rate of cold water [6], [11]. Visual observations [11] during the outflow of boiling water through an orifice showed that a stream of liquid without steam passes through the orifice, and the process of steam formation begins beyond the orifice.

There have been attempts to explain the physical aspect of the process of water outflow by a metastable state—superheating of the water. However, from-

It is known that, in order to obtain stable states of superheated water, it is necessary to satisfy a whole series of conditions, the fulfillment of which is difficult to ensure under the conditions of boiling-water outflow: there must be no pulsations, no dissolved gases, and no foreign impurities in the liquid.

In reality, vapor formation is observed not in the diaphragm itself, but downstream of it, because the process of vapor formation proceeds at a definite rate and requires a definite interval of time for its completion. There are no data on the rate of the vapor-formation process during outflow. Under stationary conditions the rate of the vapor-formation process was determined in experiments by Zysina and Kutateladze [12]. By means of high-speed photography it was established that, during boiling under atmospheric conditions, the emergence, growth, and detachment of a single vapor bubble in a medium require a time interval of 0.0285 seconds. But the process of vapor formation is not completed by this. After the bubbles detach from the walls, the process of vapor formation continues within the volume of the liquid. In all, counting also the boiling time within the liquid volume, completion of the vapor-formation process, according to experimental data, requires a time interval of 0.02–1 seconds.

If the time interval required for vapor formation is compared with the residence time of liquid particles inside the nozzle, it turns out that the process of water outflow occurs several times faster than the vapor-formation process. This leads to the result that, in outflow through thin diaphragms, the boiling liquid flows out practically without steam. In outflow through nozzles whose length is several times greater than the diameter of the orifice, the vapor-formation process will be completed the more fully, the longer the nozzle and the smaller the pressure difference under which the outflow occurs, i.e., the longer the time interval during which the particles of boiling liquid remain inside the nozzle. Consequently, in the theoretical works considered, the explanation of the boiling-water outflow process admits the incorrect assumption of complete development of the vapor-formation process during the residence time of the liquid particles inside the nozzle. The process of boiling-water outflow cannot be considered a reversible process, such as the process of adiabatic expansion of steam, since in the process of boiling-water outflow there is a mismatch between pressure and temperature.

II. EXPERIMENTAL INSTALLATION AND MEASUREMENT PROCEDURE

The experimental study of the process of boiling-water outflow was carried out on diaphragms and cylindrical nozzles of various lengths. In the experiments, the throughput capacity of nozzles for boiling and cold water was determined as a function of the initial pressure, the distribution of static pressure along the length of the nozzles was determined, and visual observations of the flow were made.

For carrying out the experiments, a special installation was assembled, the diagram of which is given in Fig. 2. Boiling water enters from the steam boiler through a pipe whose end is lowered below the upper water level in the boiler. Onto the upper end of the pipe is screwed a flange with a nozzle screwed into it. An observation chamber is fastened to the flange. The chamber is provided with windows for observation and with a valve for regulating the water level. Water from the observation chamber flows into a measuring tank through the lower pipe—cooler. The steam formed in the observation chamber condenses in the upper pipe—condenser. The condensate flows into the observation chamber and from it into the measuring tank. From the measuring tank the water is discharged into a reservoir, from which it is drawn…

Fig. 2. Diagram of the experimental setup:
1 — steam boiler; 2 — tube for water intake; 3 — nozzle under test; 4 — observation chamber;
5 — cooler tube; 6 — condenser tube; 7 — collecting vessel; 8 — feed-water tank;
9 — feed pump; 10 — water U-tube manometer; 11 — electric heaters.

is sent to feed the boiler. The upper pipe—the condenser and measuring tank for maintaining atmospheric pressure inside them—communicates with the atmosphere. The boiler is heated by an electric heater.

The diaphragms and cylindrical nozzles were made of brass. The holes in them were drilled and then finished with a reamer. In the nozzles in which the pressure was measured along the length of the nozzle, lateral holes were drilled. The holes were drilled with a diameter of 3.0 mm, and at the point of exit into the channel—0.5 mm. Tubes were soldered into the holes, to which the connecting tubes of the manometers were attached.

The pressure in the boiler from 0.02 to 0.4 ati was measured with a water manometer with a scale division value of 1 cm of water column; from 0.4 to 1.2 ati and higher—with a spring manometer with a scale division value of 0.1 ati—1.0 ati. The pressure along the length of the nozzle was measured by means of U-shaped mercury manometers with a scale division value of 1.0 mm.

The boiling temperature of the water was measured by means of a mercury thermometer with a scale division value of 0.1°C. The purpose of the temperature measurement was to determine the established boiling regime of the water.

The flow rate was determined from the time required to fill a previously calibrated volume of the measuring tank by measuring the water level by the water-gauge glass on a scale with a division value of 1.0 mm.

The total error in determining the discharge capacity, taking measurement errors into account, was ±3.6%.

III. DESCRIPTION OF THE EXPERIMENTS AND THE RESULTS OBTAINED

First series of experiments. The purpose of the experiments was to determine the discharge capacity of cylindrical nozzles with cold and boiling water. The experiments were carried out on a laboratory boiler at a pressure of 1.2 ati. In the experiments with cold water, the excess pressure was created by a pump. Readings—

measurements of the flow rate were made after the pressure had become steady: every 0.04–0.05 at up to a pressure of 0.4 ati, and every 0.1 at in the remaining cases. In the experiments with boiling water, the pressure was regulated by the number of heaters switched on and by discharging steam to the atmosphere. Flow-rate readings were taken after the pressure and temperature had become steady. The boiler was fed periodically with heated water, in small portions. During individual experiments, visual observations were made.

The results of the experiments are presented in Figs. 3 and 4. In the latter are given photographs of the stream downstream of the nozzle during the outflow of cold and boiling water. The photographs were taken with illumination through the observation chamber. The exposure time was 0.005 s.

Second series of experiments. The purpose of the experiments was to measure the pressure along the length of the nozzles, but at the same time their throughput capacity was also determined. The results of the experiments are presented in Fig. 5, where the values of the throughput capacity of the nozzles are given, and in Fig. 6, where the results of measuring the pressure along the length of the nozzle are presented.

Third series of experiments. The purpose of the experiments was to determine the throughput capacity of the nozzles at pressures in the boiler from 1.0 to 8.0 ati. The experiments were carried out on a Shukhov–Berlin boiler in the institute boiler room, to which the measuring part of the experimental installation had been transferred. The results of the experiments are presented in Fig. 7. Data on the throughput capacity of cylindrical nozzles with cold water for this series of experiments were calculated from the formula for the outflow of cold water:

\[ G_{x.v}=f\cdot\mu\cdot\gamma_{k.v}\sqrt{2g(p_1-p_2)v_{x.v}} \quad \text{kg/sec} \tag{10} \]

The value of the discharge coefficient was taken from the data of [13].

DISCUSSION OF THE EXPERIMENTAL RESULTS

1. GENERAL CONSIDERATIONS ON THE PHYSICAL PICTURE OF THE FLOW

From observations and photographs of the flow, the external difference between the process of outflow of boiling water and that of cold water is apparent. Thus, when cold water flows out, a smooth, transparent jet issues from the nozzle (Fig. 4, a), whereas when boiling water flows out, the jet becomes covered with a matte coating and is often broken up by steam bubbles arising on its surface.

In the case of outflow into a flooded space, the jet of cold water is washed out and dissipates, causing only a vortical motion of the water (Fig. 4, b); when boiling water flows out, a clearly visible jet of steam appears (Fig. 4, g); with a large pressure difference, the steam jet expands immediately after the nozzle, forming a continuous column of steam (Fig. 4, d, e). The process of outflow of boiling water differs from that of cold water also in the pattern of pressure distribution. When cold water flows out, an almost complete pressure drop to the back pressure occurs in the inlet section, whereas when boiling water flows out the pressure along the length of the nozzle decreases somewhat and finally falls to the back pressure in the outlet section (Fig. 6, a, b, v, g, d, e). As is known, a similar pattern of pressure change along the length of a nozzle is observed during the outflow of cold water through a pipeline with an orifice plate or with a partially open valve in the outlet section [14]. It follows from this that, during the outflow of boiling water through cylindrical nozzles, the through-flow area for the liquid part of the flow decreases, which occurs as a result of the formation of steam inside the nozzle. The pattern of pressure change along the length of the nozzle thus makes it possible to deter-

Figure 3. Dependence of the discharge capacity of cylindrical nozzles of various lengths on the pressure difference, according to experimental data.

Vertical axis: discharge capacity, kg/(s·cm²).
Horizontal axis: pressure, kgf/cm².

Legend:
—○— boiling water
– – – cold water

Subfigures:

a) \(\ell = 10\) mm, \(\ell/d = 0.5\)

b) \(\ell = 70\) mm, \(\ell/d = 3.5\)

c) \(\ell = 32\) mm, \(\ell/d = 16\)

d) \(\ell = 48\) mm, \(\ell/d = 24\)

e) \(\ell = 92\) mm, \(\ell/d = 46\)

f) \(\ell = 0.3\) mm, \(\ell/d = 0.15\)

Fig. 4. Photographs of the jet after the nozzle during discharge:

a) cold water into free space at \(p_1 = 0.05\ \text{kg/cm}^2,\ t_{\mathrm{в}} = 22^\circ\text{C}\).
b) cold water into a flooded space at \(p_1 = 0.5\ \text{kg/cm}^2,\ t_{\mathrm{в}} = 22^\circ\text{C}\).
c) boiling water into a flooded space at \(p_1 = 0.05\ \text{kg/cm}^2,\ t_{\mathrm{в}} = 100.8^\circ\text{C}\).
d) the same at \(p_1 = 0.116\ \text{kg/cm}^2,\ t_{\mathrm{в}} = 102.8^\circ\text{C}\).
e) the same at \(p_1 = 0.38\ \text{kg/cm}^2,\ t_{\mathrm{в}} = 109^\circ\text{C}\).
f) the same at \(p_1 = 0.7\ \text{kg/cm}^2,\ t_{\mathrm{в}} = 115.3^\circ\text{C}\).

Fig. 5. Dependence of the discharge capacity of cylindrical nozzles of various lengths on the pressure difference, according to experimental data.

Vertical axis: Discharge capacity, \(\mathrm{kg}/(\mathrm{s}\cdot\mathrm{cm}^2)\).
Horizontal axis: Pressure, \(\mathrm{kg}/\mathrm{cm}^2\).

Legend: solid line with circles — boiling water; dashed line with squares — cold water.

Subfigures:

• a) \(\ell = 16\ \mathrm{mm},\ \ell/d = 3.4\)
• b) \(\ell = 14\ \mathrm{mm},\ \ell/d = 6.4\)
• c) \(\ell = 31\ \mathrm{mm},\ \ell/d = 14\)
• d) \(\ell = 80\ \mathrm{mm},\ \ell/d = 36.5\)
• e) \(\ell = 120\ \mathrm{mm},\ \ell/d = 54.6\)
• g) \(\ell = 50\ \mathrm{mm},\ \ell/d = 23\)

Fig. 6. Change in pressure along the length of the nozzle during the outflow of cold and boiling water, according to experimental data.

a) \(l = 70\ \mathrm{mm},\ \psi_d = 3.4\)

Cold water

Boiling water

Pressure, \(\mathrm{kg}/\mathrm{cm}^2\)

b) \(l = 14\ \mathrm{mm},\ \psi_d = 6.4\)

c) \(l = 31\ \mathrm{mm},\ \psi_d = 14\)

d) \(l = 50\ \mathrm{mm},\ \psi_d = 23\)

e) \(l = 80\ \mathrm{mm},\ \psi_d = 36.5\)

f) \(l = 120\ \mathrm{mm},\ \psi_d = 54.6\)

Legend:

— × — at \(p = 0.1\ \mathrm{kg}/\mathrm{cm}^2\)

— □ — at \(p = 0.4\ \mathrm{kg}/\mathrm{cm}^2\)

— △ — at \(p = 0.8\ \mathrm{kg}/\mathrm{cm}^2\)

— ○ — at \(p = 1.2\ \mathrm{kg}/\mathrm{cm}^2\)

Fig. 7. Dependence of the throughput capacity of cylindrical nozzles of various lengths on the pressure difference, according to experimental data.

Vertical axis: Throughput capacity, kg/(sec·cm²)

Horizontal axis: Pressure, kg/cm²

Additional horizontal scale: Undercooling of water, °C

Legend:

—○— boiling water
– –○– cold water

a) \(l = 1\) mm, \(l/d = 0.4\)

b) \(l = 8\) mm, \(l/d = 3.1\)

c) \(l = 12.5\) mm, \(l/d = 4.8\)

d) \(l = 32\) mm, \(l/d = 14.5\)

e) \(l = 48.5\) mm, \(l/d = 22\)

f) \(l = 92\) mm, \(l/d = 42\)

...determine the fraction of the cross section occupied by steam and, consequently, judge the course of the vaporization process.

When cold water flows out, compression of the stream occurs at the inlet section. Then the jet gradually expands and flows out with a full cross section. In the cavity of the contracted section that has formed, air is entrained by the flow of the jet. In this zone a vacuum pressure is produced, the magnitude of which may be lower than the saturation pressure of water (Fig. 8, a). In this case, steam forms in the region of the contracted section. The steam that has formed, moving along the walls of the nozzle, causes separation of the jet from the nozzle walls and communication of the region of the contracted section with the atmosphere. After this, the pressure in the contracted section increases to atmospheric pressure and boiling ceases. Then a vacuum pressure is again created, and the process repeats.

Fig. 8. Flow shape and pressure variation during outflow through cylindrical nozzles:
a — cold water, b — boiling water.

Obviously, when boiling water flows out, the phenomenon considered will also be observed. But in the case of outflow of cold water, the break in the vacuum pressure caused the boiling to cease, whereas in the case of outflow of boiling water this process will not be interrupted. Steam bubbles are constantly nucleated and grow on the inner surface of the nozzle; upon detaching, they are carried out of the nozzle together with the flow. With intense vaporization they may form a continuous ring of vapor–liquid mixture, which moves together with the flow. In the outlet section a pressure drop occurs, as a result of which the vapor flow expands, causing contraction of the cross section of the liquid part of the flow (Fig. 8, b).

The described character of the flow in the nozzle is not consistent with the results of observations of vaporization in boiler tubes of steam boilers. According to [15], in this case steam bubbles forming on a vertical surface detach from it in a direction perpendicular to the surface and, after describing an arc, rise upward along the middle of the tube. The reason for the discrepancy becomes clear if one compares the trajectories of the bubbles in the two cases. In boiler tubes the velocity field is established, i.e., nonuniform. Near the tube walls the velocity is close to zero. When boiling water flows out through nozzles, the flow is not yet established; the velocities over the cross section are approximately the same. The steam bubbles move in a straight line, almost parallel to the axis of the flow (Fig. 9). Consequently, in the presence of an unestablished velocity field (the latter is observed in the inlet section of the nozzle over a length of 50–60 orifice diameters), a flow may arise in the form of a liquid core surrounded by steam.

In nozzles with a length greater than the length of the stabilization section, the indicated type of flow will not be preserved. The nonuniform velocity field will cause...

turbulization of the flow, as a result of which an emulsion type of flow arises, in which the steam and liquid are mixed with one another and are almost in a state of thermodynamic equilibrium.

In light of the foregoing, it is appropriate to analyze the results of the experimental data on temperature measurements along the length of the nozzle, carried out by Adam [6]. These measurements gave “contradictory” results. It turned out that, during the outflow of boiling water from short nozzles, superheating of the liquid by 15–40° C was detected, whereas in experiments with long nozzles phenomena of thermodynamic correspondence were observed. In our interpretation the results of these experiments are quite natural. During outflow from short nozzles, vapor formation does not have time to develop, and the water will flow out superheated. In long nozzles, completion of vapor formation and the presence of thermodynamic correspondence are possible.

2. THROUGHPUT CAPACITY OF ORIFICES AND NOZZLES FOR BOILING WATER

The throughput capacity of orifices for boiling water, as experiments show, is somewhat reduced in comparison with their throughput capacity for cold water, which is explained by the decrease in the specific weight in boiling water.

The throughput capacity of orifices for cold water is equal to:

\[ G_{\mathrm{c.w.}} = f \cdot \mu \cdot \gamma_{\mathrm{c.w.}}\sqrt{2g(p_1-p_2)v_{\mathrm{c.w.}}}\ \mathrm{kg/sec}. \tag{10} \]

For the case of boiling-water outflow:

\[ G_{\mathrm{b.w.}} = f \cdot \mu \cdot \gamma_{\mathrm{b.w.}}\sqrt{2g(p_1-p_2)v_{\mathrm{b.w.}}}\ \mathrm{kg/sec}. \tag{11} \]

From (10) and (11) we obtain

\[ \frac{G_{\mathrm{b.w.}}}{G_{\mathrm{c.w.}}} = \left( \frac{\gamma_{\mathrm{b.w.}}}{\gamma_{\mathrm{c.w.}}} \right)^{1/2} \tag{12} \]

Since \(\gamma_{\mathrm{b.w.}} < \gamma_{\mathrm{c.w.}}\), then \(G_{\mathrm{b.w.}} < G_{\mathrm{c.w.}}\).

The indicated dependence is confirmed by the results of experiments. Consequently, the throughput capacity of orifices for boiling water can be determined from the formula for the outflow of cold water, if the value of the specific weight of boiling water is substituted into it.

It was indicated above that, according to the data of [10], the throughput capacity of ori-

Fig. 9. Trajectory of motion of a vapor bubble inside during the outflow of boiling water.

Labels in the figure: \(w_{\text{flow}}\); \(10^{\circ}\) to the horizon; velocity field; pressure field.

the orifice on boiling water is equal to 0.25 of the discharge capacity on cold water. Such results could have been obtained only with counterpressure downstream of the orifice.

When boiling water flows through cylindrical nozzles, as the experiments showed, their discharge capacity is less than on cold water. We calculated the discharge capacity of cylindrical nozzles from the magnitude of the pressure drop at the nozzle inlet, using the formula for the outflow of cold water. The calculation shows agreement between the calculated results and the experimental data. The latter makes it possible to recommend the indicated method for calculating the discharge capacity of cylindrical nozzles on boiling water. For this purpose, in formula (10), instead of the total pressure difference, one should substitute the magnitude of the pressure drop in the inlet section, i.e., write it in the form:

\[ G_{k.v}=f\cdot \mu \cdot \gamma_{k.v}\sqrt{2g(p_1-p_{cc})v_{k.v}}\ \text{kg/sec}, \tag{13} \]

where \(p_1-p_{cc}\) is the pressure difference in the inlet part of the nozzle.

Using formula (13), calculations were made of the magnitude of the pressure drop according to the results of the third series of experiments. The data obtained showed the dependence of the magnitude \(p_1-p_{cc}\) on the nozzle length in the form:

\[ p_1-p_{cc}=(p_1-p_2)\left[0.71-\log (l/d)^{1/3}\right]\ \text{kg/cm}^2 \tag{14} \]

After substituting (14) into (13), we obtain:

\[ G_{k.v}=f\cdot \mu \cdot \gamma_{k.v} \sqrt{2g(p_1-p_2)\left[0.71-\log (l/d)^{1/3}\right]\cdot v_{k.v}} \ \text{kg/sec} \tag{15} \]

If the magnitude of the change in specific weight during the heating of water is neglected and it is assumed that \(\gamma_{k.v}=\dfrac{1}{v_{k.v}}=1000\ \text{kg/m}^3\), then, taking the constant value of the discharge coefficient \(\mu=0.62\) and replacing \(f\) by \(\dfrac{\pi d^2}{4}\), we obtain formula (15) in the following form:

\[ G_{k.v}=24d^2\sqrt{(p_1-p_2)\left[0.71-\log (l/d)^{1/3}\right]}\ \text{kg/hour}. \tag{16} \]

Conclusions

1. The following have been obtained: a) experimental data on the discharge capacity, on boiling water, of orifices and cylindrical nozzles of diameter \(2\text{–}2.6\ \text{mm}\) and length \(1\text{–}120\ \text{mm}\); b) experimental data on the pressure variation along the length of cylindrical nozzles of diameter \(2\text{–}2.6\ \text{mm}\) and length \(8\text{–}120\ \text{mm}\).

2. Visual observations and photography of the process of outflow of boiling water were carried out.

3. Calculation methods were obtained for determining the discharge capacity of orifices and cylindrical nozzles of diameter \(2.0\text{–}2.6\ \text{mm}\) and length \(1\text{–}120\ \text{mm}\) at pressure differences of \(0.02\text{–}8.0\) ati.

Literature

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