## 3 Experimental Design  
### Theory of Sea Surface Infrared Calculations  
(1) Device for simulating underwater waves  
Using the wind-wave-current multifunctional experimental tank of the State Oceanic Administration's First Institute of Oceanography, Figure 1 shows the schematic diagram of the wind-wave-current multifunctional experimental flume. Figure 2 is a photograph of the experimental wind-wave-current water tank. The tank is 45 m long in total. A booster chamber is located at either end of the 32.4 m long, 1 m wide, and 1.8 m deep glass tank (5.2 m long and 3.0 m wide). The steel frame that surrounds the glass tank has laminated glass on both of its sides and at the bottom. The wavemaker is mounted at the top of the tank. Energy-dissipating rectification grilles are fitted at the wavemaker's back and at the end of the tank. Installed in the gallery at the base of the tank, the pump and circulating flow pipe are connected to the booster chamber at both ends. The tank's operating depth ranges from 0.2 to 1.2 m. The surge model may be used to train the wave-generation system to perform a variety of wave-generating tasks, including producing regular waves and irregular waves and breaking by superimposing various component waves. The experimental underwater vehicle was selected from the Tianjin Deep Blue \"White Shark MAX\" ROV, with dimensions of 590 mm \(\times\) 510 mm \(\times\) 330 mm, a weight of 15 kg, and a working depth up to 100 m, which can be remotely controlled by remote control. Figure 3 shows the tail flow experimental vessel. Figure 1: Schematic diagram of the wind–wave–current multifunctional experimental flume: (1) glass-flume; (2) wavemaker; (3) booster chamber; (4) return duct; (5) fan; (6) flume foundation and bottom gallery; (7) return duct. Figure 2: Wind–wave–current multifunctional experimental flume site photo. (3) Infrared camera parameters  
A Xenics-Gobi 640-GigE long-wave infrared camera was used for this experiment, with specific camera parameters and images shown in Table 1 and Figure 4 below. ### Theory of Sea Surface Infrared Calculations  
Based on the similarity principle in fluid dynamics, a geometric similarity ratio of 1:128 was used. The program that was written simulates an underwater surge at various heights. An underwater surge at different heights was achieved by a real-time capture of the infrared camera and the temperature correction by contact thermometry. The control of jet flow and flow velocity was achieved by tank pressurization injection and fixed bore. The following is a list of the experimental steps. An upward image of the water's surface from a 60-degree angle was captured using a long-wave infrared camera attached to the gantry. To simulate a submarine thermal jet, \begin{table}
\begin{tabular}{c c} \hline \hline
**Camera Models** & **Xenics-Gobi 640-GigE** \\ \hline Infrared Band & 8 \(\upmu\)m\({}^{-1}\)\(\upmu\)m \\ \hline NETD & 55 mk \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The IR camera parameters. Figure 4: Xenics-Gobi 640-GigE long-wave infrared camera. Figure 3: Tail flow experimental vessel. a jet pipe attached to the stern of the model submarine was used to inject hot water into the water under pressure through a 3 L container with a drain pipe diameter of 5 mm at an average discharge rate of 600 mL/min (the discharge temperature of the outlet was recorded in real time during the experiment as the drain pipe exchanged heat with the surrounding environment and there was attenuation during the discharge process). An autonomous submersible that can be programmed to obtain precise depth and speed settings was used to replicate the undersea submarine. The submersible's speed was adjusted to 2.4 m/min to be as near to the actual circumstance of a subsurface cooling water outflow as possible.