# Temperature Fields of the Droplets and Gases Mixture
## 3 Results and Discussion
### Adjustment and Generalization of Measurement Results  
After analyzing the thermocouple temperature results, we introduced coefficient \(K\) with regards to the LIP results to adjust the thermocouple measurements. Coefficient \(K\) is calculated as a ratio of LIP-measured temperature to thermocouple-measured temperature for each experimental point: \(K=T_{\text{LIP}}/T_{\text{Therm}}\). Typical variations of \(K\) are shown in Figure 10. From the results of the \(K\) calculation, we can see its continuous variation with time. For all the experiments, deviation of \(K\) from 1 is lower than 0.1-0.15, that is, prior to droplet injection and after the temperature recovery (areas 1 and 4). This is due to the accuracy level of the LIP technique. The maximum \(K\) is observed when the temperature recovers (rises) in the trace of the droplet flow (area 3, Figure 10), which is explained by the delay of the thermoelectric converter. It can be seen from Figure 10 that thermocouple measurements need to be adjusted at this very stage (area 3). For the case of heated air (Figure 9(a)), the adjustment leads to an increase in the temperature readings, and, consequently, to a slight (5-15%) decrease in the maximum temperature fluctuations \(\Delta T_{\text{a}}\). The reverse is true for the case of combustion products flow (Figure 9(b)), when the actual temperature in the trace is lower than the thermocouple readings, and the adjustment increases \(\Delta T_{\text{a}}\) by 20-30%. This effect is worth considering when predicting the maximum drop of the gas temperature in the trace of a gas-vapor-droplet flow. Thus, with the help of coefficient \(K\) we can adjust the readings of thermoelectric converters (make temperature readings closer to actual values) in cases when using non-contact measurement tools does not seem possible. Figure 10: Variation of the adjusting coefficient \(K\) in the trace of a droplet flow (\(I\): prior to droplet injection; 2: \(T_{\text{a}}\) temperature drop to the lowest value; 3: \(T_{\text{a}}\) temperature growth; 4: \(T_{\text{a}}\) temperature recovery): (**a**) heated air flow; (**b**) kerosene combustion products flow. Figure 11 shows the dimensionless lifetime of low temperature (\(\tau/t_{\text{imp}}\)) and the dimensionless gas-vapor-droplet mixture temperature in the trace of a droplet flow versus Reynolds number (Re calculated as in [21] considering droplet and gas flow velocity). The figure provides the LIP results and the experimental data from [21]. We can see the results from multiple experiments with thermocouples placed in different gas-vapor-droplet trace sections and taking into account the droplets cloud polydispersity. The generalization of our experimental results and data from [21] shows that complete recovery times of temperature fields after droplet and gas flow blending are very close (experimental data from contact and non-contact measurements correspond well in Figure 11a). The maximum temperature variation of the gas-vapor mixture differs significantly in Figure 11b. This result shows enough room for improvement of findings [21] in terms of exploring maximum (short-time peak values) gas-vapor mixture temperature variations that were difficult to record by thermocouples. This becomes possible with the application of non-contact recording techniques reviewed in the present work. The gas-vapor-droplet technologies [35; 36; 37; 38; 39; 40; 41; 42; 43] use water-based solutions and emulsions as the operating fluid for the defrosting of granular materials, treatment of thermally loaded surfaces of power equipment, thermal or flame treatment of water, production of heat transfer fluids, firefighting, etc. One of the main problems when defining the parameters of all the above applications is the reliable prediction of droplets and vapor temperature and concentration. Using the technique presented in the present work, this can be achieved with high reliability and speed.