Experimental Study of Effect Vertical Vibration on Heat Transfer of Vehicle Radiator

Due to the paucity of prior research on cooling system optimization, which frequently concentrated on enhancing thermal performance under optimal operating circumstances while ignoring the combined effects of these elements, this study was selected. In order to handle vibrations and sustain thermal performance under a variety of operating conditions, cooling systems must be designed and optimized. This clearly causes a research gap. As a result of the temperature difference between two adjacent bodies, heat transfer occurs from the hotter surface to the cooler surface to reach thermal equilibrium. There are three types of heat transfer: conduction, convection, and radiation [1]. Convection heat transfer has received widespread attention from researchers and is the most frequently used in industrial application.

Heat transfer enhancement methods are classified, based on their energy requirements, into active, passive, and composite-enhanced heat relies on surface vibration [2], magnetic field [3], spraying [4], and mechanical movement for heat transfer [5]. Passive technology relies on the use of a rough, extended surface [6], the jet [7], effect of surface treatment [8], and composite reinforcement of active and passive processes is achieved using various method.

Engineering applications have shown that heat transfer is of great importance in the design of bridges, buildings, vehicles, and digital devices, as well as in the development of heat transfer systems such as heaters, radiators, and heat exchangers [9]. Heat generation in these systems can lead to overheating and consequent system failure [10]. To eliminate this problem, practical studies are required on the transfer of heat from a solid surface to the fluid in contact with it [11].

In recent years, due to global advancements, car models have evolved and become more complex, leading to a need for larger radiators and improved performance [12]. The radiator is a crucial component of cooling systems, dissipating excess engine heat through heat transfer [13].

Due to rough roads or internal car design problems that cause vibrations, and because studies in this area were insufficient, this research idea was applied to determine the effect of vibrations on heat transfer. Vibrations disrupt the fluid surface in the boundary layer, leading to increased mixing between surfaces, which in turn increases heat transfer via convection.

Vibration is an effective and successful method for increasing heat transfer, as it confuses the particles in the fluid layers, leading to increased heat transfer [14]. There are two methods for vibration: the first is to keep the surface stationary, and to apply vibration within the liquid medium around the surface. The second is the movement of the surface itself as a result of placing a mechanism that forces the surface to vibrate, while the surrounding medium remains constant [15]. In industrial applications, when exposed to vibration (vibration resulting from ultrasonic waves and pulsating flow), despite its negative effects on the life and durability of the devices, the improvement of thermal transfer is achieved many times without vibration [16], [17]. The acoustic field [18] and nano particles [19], [20], [21], [22] are considered important methods for increasing thermal transfer It is considered the best way to cool the computer [23]. Among the negative effects are concerns about the effect of vibration when designing machines under dynamic conditions due to their operation [24]. The effect of Nusselt number and Rayleigh number on improving thermal performance was investigated when heat was added using two shaped fins, one perforated and the other non-perforated. Heat transfer rate and Nusselt number increased with increasing heat addition, and increasing Rayleigh number resulted in a decrease in thermal resistance. It was confirmed that the non-perforated fin performed better than the perforated fin in improving thermal performance Also, injecting air bubbles into the U-shaped two-tube heat exchanger resulted in an increase in the flow rate and an increase in the heat transfer coefficient [25], [26]. Sheikh et al. [27] studied the effect of heat exchangers on the heat transfer process of thermoelectric generators using nine heat exchanger models. The results showed that reducing the barrier in the middle of the heat exchanger to 2.3 mm reduces the energy by a certain percentage 10.83%. Masoud Hosseini et al. [28] presented a study on improving thermal performance using low-concentration nanofluids in a long-tube heat exchanger. They found that when a concentration of 0.055% of the nanofluid is applied, the heat transfer process increases significantly and noticeably.

Eid and Gomaa [29] used a heat sink to demonstrate the effect of vibrations on heat transfer. The sink consisted of thin, flat fins. The sample was heated by a heater at the bottom and then subjected to vibration via a cam disc in random directions. The results showed that the Reynolds and Nusselt numbers were correlated, and the highest increase in the heat transfer rate was 85% compared to the static state.

Also, using a diffuser consisting of long fins, Sarhan [30] investigated the effect of vibrations occurring in a range (12–16 Hz) in the horizontal and inclined positions at angles (30°, 60°, and 90°). The results showed that the heat transfer coefficient at the angle 30° was higher than at the angle 60° by a certain amount 19.27%, and that the greatest increase at the angle 90° was 31.49% the increase in the heat transfer coefficient. Through practical and theoretical application, Kadhim and Mery [31], [32] conducted a study to clarify the effect of forced vibrations on the heat transfer coefficient of a wave-shaped copper surface subjected to vibration ranges (5 to 25 Hz) with varying amplitudes (3, 4, and 5 mm). The Rayleigh number (1.5 × 10⁸– 4 × 10⁸) was heated in three ways: vertically, horizontally, and from above. It was found that increasing vibration increases the Nusselt number for the applied conditions, but this depends on the position of the wave surface. The transfer coefficient depends on the ratio between the vibration amplitude and the wavelength, with the best increase occurring at a ratio of 0.3.

Due to the phenomenon of reverse flow on inclined surfaces, the flow at lower Reynolds numbers is less stable. This was demonstrated by T’Joen et al. [33] using an inclined fin with a long tube, and he found that the best heat transfer occurs when the flow is along the fin. Biswas et al. [34] presented a review of the use of long vortex generators and how they improve thermal performance by disrupting the thermal boundary layer. The study of heat transfer enhancement has always been linked to pressure loss, and both lead to a good balance. In his scientific study, Li et al. [35] proposed the effect of vertical vibration on a radiator and how it impacts thermal performance. The experiment was conducted at a specific frequency, and it was found that the heat transfer coefficient increased with the gas side to a maximum of 16.82%, and with the air side to a maximum of 11.71%. Increasing the vibration increases heat transfer and results in pressure loss. However, despite the pressure loss, the improvement in thermal performance outweighs the pressure loss, and the highest increase in heat flow was found to reach 51.50%. The addition of nanoparticles and their ability to further enhance heat transfer. Sarafraz et al. [36] presented a study on the use of an iron oxide nanofluid, finding that despite a 37.5% pressure reduction, heat transfer increased by 46.3%. This suggests that nanofluids significantly contribute to increased heat transfer rates. Furthermore. Li et al. [37] demonstrated that adding an acetone and carbon nanofluid to heat exchangers increased heat transfer by up to 73%. Similarly, Goodarzi et al. [38] used counter-current heat exchangers and found that the presence of nanomaterials increased the Reynolds number, which in turn improved heat transfer efficiency using nanofluids. Using graphene nanosheets, researchers Bahiraei et al. [39] and Sarafraz et al. [40] have improved thermal performance through convection. Bahiraei demonstrated that increasing the Reynolds value from 1000 to 3000 resulted in up to 142% improvement in the performance of the nanofluid, while Sarafraz found a 32.1% improvement.

Mohammed et al. [41] used a rectangular channel heat exchanger to demonstrate the effect of vibration on improving thermal performance. They conducted experiments at three different frequencies and found that increasing vibration led to increased heat transfer. Similarly, Pandey et al. [42] used a horizontal heat exchanger and conducted their experiment with and without vibration. They found that the presence of vibration increased heat transfer, but only to a certain extent. Using very high frequencies can cause problems in the heat exchanger, potentially leading to its damage, such as noise, leakage, and reflections. In heat transfer Tian et al. [43] using a helical twin-tube heat exchanger, heat transfer was increased by converting the fluid’s motion into a secondary, slower motion via forced convection. Bahmani et al. [44] also demonstrated increased heat transfer of nanofluids by increasing the Reynolds number.

The purpose of this study is to find strategies to improve thermal performance in finned-tube car radiators by increasing volumetric flow rates. Analyzing how vibrations improve heat transfer inside the radiator is another goal. The evaluation of heat dissipation’s contribution to lower operating temperatures and improved heat exchange efficiency is the main goal of the study. Additionally, it aims to assess the radiator’s thermal performance before and after implementing the suggested improvement methods.

Lastly, the study attempts to offer workable methods that might be applied to enhance automobile radiator efficiency and design.

The Figure 1 shows the design of the test platform under vibration conditions.

The platform consists of a radiator, a vibration shaker, and a tank equipped with a heater connected to a booster and flow meter. The radiator is placed on the vibration shaker platform, and vertical mechanical frequencies are generated. The frequency used in this experiment is (5, 10, and 15 Hz), which is similar to the vibrations experienced by vehicle radiators due to road roughness or internal engine vibrations. The forced frequencies generated by the vehicle are often low, hence the use of this vibration range. Flexible pipes circulate the water between the radiator and the tank, a principle similar to how cars operate. The water circulates between the engine, becoming hot, and returns to the radiator where the heat is dissipated by convection between the water and air. Temperature and flow data obtained during the experiment were collected. The Figure 2 illustrates the device used under vibration conditions, and the Table 1 shows the engineering specifications used for the radiator.

Flow and vibration parameters and physical properties are as follows:

Water flow was measured using a flow meter consisting of two scales: gallons per minute (GPM) and liters per minute (LPM). The standard was LPM, and the water flow values used were 0.5, 0.75, 1, and 1.25 LPM.

Temperature sensors are measured using a Data Logger device with 8 temperature measurement channels: two at the water inlet and outlet of the radiator, five pairs distributed on either side of the radiator, and one free to measure ambient temperature. The device features a digital display showing the temperatures.

Vibration Meter is a device (SinometerVM-6360) was used to measure the acceleration and speed of vibration. It is attached to a magnetic compass placed on the vibration meter platform. The shaker converts the physical sensor into signals that are recorded on its digital screen. It works vibration for range (0–1 kHz). A heater was installed on the water tank to heat the water and set the temperature at 55℃.

The parameters obtained include the water inlet and outlet temperatures of the radiator, the ambient temperature of the radiator, and measurements. The parameters obtained included the inlet and outlet temperatures of the radiator water, the ambient temperature of the radiator, water flow rate, and vibration intensity. The radiator was placed on a vibration platform and kept vibrating for 30 minutes for each operating reading. The average values of the readings were obtained, and the difference between the inlet and outlet temperatures was approximately 6 to 10 degrees Celsius.

The principle of vibration involves converting electrical energy into mechanical energy using a motor. This utilizes the principle of hydro mechanical force, creating precise vibrations by introducing an electric current into a magnetic field to generate a kinetic force. The vibration intensity can be adjusted via a control panel, and the signal is controlled by the vibration frequency, Table 2 shows the accuracy of the measurement and sensors used in this research.

In order to increase accuracy, a total of 16 measurement points were carried out under four volumetric flow rates 0.5/0.75/1/1.25 LPM in a steady-state environment free of vibrations and excitation frequencies 5/10/15 Hz. Each measurement was repeated 4 times. Excellent repeatability was shown by the deviation among repetitions not passing one unit (STDEV.S $<$ 1).

In order to prevent unintentional interference with the natural convection process, which is primarily driven by free convection, the experiments were carried out in a closed room with still air. No forced ventilation or external air flow was present during the tests, and there was no air conditioning system nearby. The updated manuscript now includes this clarification.

The periodic acceleration of the fluid caused by vertical vibration results in secondary flows. By encouraging mixing between near-surface and far-surface fluid layers, these fluxes lessen the thickness of the boundary layer and enhance heat transfer efficiency. Since the predominant fluid movement in this instance is mostly vertical, shear effects are less noticeable.

A vibration measurement instrument was used to directly measure all vibration frequencies; no values were estimated. A mechanical shaker that was intended to produce a vertical sinusoidal vibration was used to vibrate the radiator. To guarantee precise vibration transmission, the radiator was securely fixed on the shaker platform.

The vibration measurement device’s sensor was used to detect the vibration frequency, and the reported data indicated the average vibration level. Table 3 summarizes the vibration parameters and classifies them as either measured or estimated.

To determine heat transfer, it is necessary to find the relationships obtained experimentally, such as Nusselt’s number, Reynolds number, and the heat transfer coefficient [45].

Cross-sectional area of flow:

The surface area between the liquid and the wall:

Characteristic length of flat tube:

Reynolds number has been found by:

Convert flow rate from LPM to m$^3$/s:

Find mass flow rate:

In this investigation, a vibration meter installed on the shaker platform was used to measure vibration frequency directly. Acceleration and vibration amplitude were not directly measured due to equipment constraints. As a result, frequency-controlled vibration conditions are the main focus of the experimental analysis. When interpreting the vibration intensity, this restriction should be taken into account.

In this investigation, a vibration meter installed on the shaker platform was used to measure vibration frequency directly. Acceleration and vibration amplitude were not directly measured due to equipment constraints. As a result, frequency-controlled vibration conditions are the main focus of the experimental analysis. When interpreting the vibration intensity, this restriction should be taken into account.

A digital vibration meter was used to measure the vibration. In order to record motion in the same direction as the applied vibration (vertical), the sensor was positioned vertically on the shaker base. Due to equipment restrictions, amplitude and acceleration could not be measured, hence the presented data represents the average frequency. Throughout every experiment, the vibration signal's waveform remained sinusoidal.

Heat rate transfer has been found by:

The heat transfer coefficient of the water side is calculated from the temperature difference between the water inlet and outlet from the radiator, in addition to its physical properties.

A portion of the energy is lost through radiation, calculated as follows [46]:

A portion of the energy is lost through radiation, calculated as follows [47]:

The manuscript has been updated to present the governing equations in full form, and all symbols are defined at their first appearance to improve clarity and allow replication of the results. To find Reynolds number ($Re$).

where, $G$ is mass flux and measured by kg/(m$^2$·s)

And to find Prandtle number ($Pr$) used:

Physical explanation: The increase in vibration Reynolds number ($R e_v$) and excitation frequency, which exacerbate periodic disturbances within the thermal boundary layer, provides a physical explanation for the enhancement of heat transmission. Higher convective heat transfer coefficients and the observed rise in the Nusselt number result from these disruptions, which also encourage boundary layer thinning and cause secondary flow and micro-mixing close to the heated surface.

Figure 3 shows the increase in the heat transfer coefficient with increasing volumetric flow rate and vibration intensity. Vibration increases turbulence, thus reducing the thickness of the boundary layer, which in turn increases collisions of water molecules, leading to heat transfer. Although the flow rate decreases the time it takes for water to enter and exit the radiator, the change in its physical properties and the increase in mass flow rate result in a higher temperature. The ratios below represent the increase in the heat transfer coefficient according to increasing volumetric flow rates at frequencies (0, 5, 10, and 15 Hz). When the volumetric flow rate was 0.5 LPM, the increase in the heat transfer coefficient was from 130.22 to 179.81 W/m$^2$·℃. At a volumetric flow rate of 0.75 LPM, the increase was from 189.08 to 279.67 W/m$^2$·℃. For volumetric flow rates at 1 and 1.25 LPM values were from 234.23 and 355.98 to 378.77 and 563.70 W/m$^2$·℃, respectively.

Figure 4 shows the increase in air-side heat transfer between the radiator and the outside air. Increasing the volumetric flow and frequency causes disturbances in the water movement within the radiator, and the vibrations disturb the outer layer surrounding the radiator. This leads to changes in the density of the air layers, thus increasing heat transfer. The results, according to the increase in frequency intensity (0, 5, 10, and 15 Hz), were as follows: at a volumetric flow of 0.5 LPM, the heat transfer coefficient increased from 16.66 to 19.28 W/m$^2$·℃; at 0.75 LPM, the values decreased from 18.81 to 22.46 W/m$^2$·℃; and at volumetric flows of 1 and 1.25 LPM, the increase in the heat transfer coefficient was from 27.67 and 33.45 to 35.26 and 47.25 W/m$^2$·℃, respectively.

The observed rise in Nusselt number can be converted into an estimated decrease in outlet fluid temperature or an increase in heat dissipation under normal operating circumstances to illustrate the data’s practical implications for vehicle cooling. This quantitative analysis demonstrates the actual effects of improved heat transfer on the cooling system’s effectiveness and performance.

To calculate the number of Nusselt units on the water side, the results obtained from the experiment were used according to Eq. (15). When comparing the experimental results with those obtained mathematically by Eq. (16) using the Sieder-Tate Equation [48], the results were very close.

Figure 5 shows the increase in Nusselt number with volumetric flow and frequency from the water side. The values according to the frequencies (0, 5, 10, and 15 Hz) were as follows: at a volumetric flow rate of 0.5 L/min, the Nusselt number increased from 0.57 to 0.79 W/m$^2$·℃; at a volumetric flow of 0.75 LPM, the increase in Nusselt number was from 0.84 to 1.23; and at volumetric flows of 1 and 1.25 LPM, the increase in Nusselt numbers were from 1.04 and 1.58 to 1.67 and 2.48, respectively.

To calculate the Nusselt number from the air side, where heat exchange occurs between the refrigerant and the outside air, heat transfer occurs due to the density difference between the layers, thus increasing heat transfer. The Nusselt number is a function of convection heat transfer; as heat transfer increases, the Nusselt number also increases.

Figure 6 shows the increase in Nusselt number with volumetric flow and frequency from the air side. The values were as follows: at a volumetric flow of 0.5 LPM, the increase in Nusselt number according to the frequencies (0, 5, 10, and 15 Hz) was from 197.74 to 227.39 W/m$^2$·℃; at a volumetric flow of 0.75 LPM, the increase in Nusselt number was from 223.02 to 263.35; and at volumetric flows of 1 and 1.25 LPM, the increase in Nusselt numbers were from 327.25 and 396.51 to 414.03 and 556.31, respectively.

The Sieder-Tate Equation was used to determine the Nusselt number as a function of the Reynolds and Prandtl numbers according to the following relation:

The results showed that the Nusselt number increases with increasing Reynolds and Prandtl numbers. When comparing the experimentally obtained results from direct measurements with those calculated using the mathematical correlations, the difference between the results was found to be very small, indicating good agreement.

The volumetric flow rates used were 0.5, 0.75, 1, and 1.25 LPM, under vibration testing at frequencies of 5, 10, and 15 Hz, in addition to the stationary condition. The lowest Reynolds number recorded was 16.16, corresponding to the stationary condition at a volumetric flow rate of 0.5 LPM, while the highest Reynolds number was 47.25, recorded at a vibration frequency of 15 Hz and a volumetric flow rate of 1.25 LPM.

The results were also compared with those reported by another researcher in a study on improving the thermal performance of an automotive radiator. Although that study employed much higher volumetric flow rates (40 and 60 LPM) within a vibration frequency range of 0–20 Hz, it similarly achieved clear and satisfactory enhancement in vibration-assisted heat transfer.

Figure 7 show the effect of the buoyancy-induced Reynolds number on the heat transfer coefficient was investigated in the absence and presence of vibration for the following volumetric flow rates: 0.5, 0.75, 1, and 1.25 LPM. As the temperature increases, the sample begins to heat up, and its height increases with the volumetric flow rate. This increases its velocity, thereby reducing the effect of viscosity, increasing mixing within the tube, and decreasing the boundary layer thickness. Consequently, the Reynolds number increases, which in turn increases heat transfer and the heat transfer coefficient. We observe an increase in the heat transfer coefficient with increasing Reynolds number (Rea) of 16.16, 18.81, 27.67, and 33.45 W/m$^2$·℃, respectively, depending on the volumetric flow rate. In the presence of vibration, mixing increases due to the oscillations, and a slight improvement in the vibrational Reynolds number (Rev) is observed. Correspondingly, heat transfer increases at a frequency of 5 Hz. The heat transfer coefficient increases at rates of 17.27, 19.67, 29.74, and 38.48 W/m$^2$·℃, at frequencies of 10 and 15 Hz. The increases in the heat transfer coefficients for volumetric fluxes are (18.18, 21.09, 32.25, 42.14) and (19.28, 22.46, 35.26, 47.25) W/m$^2$·℃, respectively.

As vibration frequency and volumetric flow rate rise, the Nusselt number and Reynolds number increase proportionately. Both the Reynolds number and the Nusselt number rise when the fluid flow rate increases because of increasing water turbulence and the creation of more convection currents. By increasing fluid turbulence, vibration improves heat transmission. Since the rate of heat transfer determines the Nusselt number, the increased heat transfer brought about by vibration raises the Nusselt number.

The effect of the enhancement ratio on the dimensional Nusselt number was studied along with the free convection air side for volume flows of 0.5, 0.75, 1, and 1.25 LPM in the presence and absence of vibration at frequency levels 5, 10, and 15 Hz. It is clear that with increasing frequency and volume flow, on the coolant side, the density of the hot air layer resulting from the temperature difference changes and is replaced by cold air. This disturbance increases as the vibration increases, and there is a difference between the cold and hot air layers. As a result, the difference occurs, free heat transfer increases as the frequency and volume flow increase, which increases the heat transfer, especially the Nusselt number, because it is a function of the heat transfer by convection. The increase in the improvement percentages of the heat transfer coefficient at frequencies 5 and 10 Hz and according to the adopted volumetric flows were as follows (3.50%, 4.26%, 7.73%, 7.82%) and (4.99%, 6.85%, 8.53%, 9.82%) respectively. The highest increase in the improvement percentage was 6.42%, 7.61%, 8.90%, and 12.99% at frequency of 15 Hz, as shown in Figure 8.

The improvement in the dimensionless Nusselt number was studied for volumetric flows of 0.5, 0.75, 1, and 1.25 LPM, in the presence or absence of vibration at frequencies of 5, 10, and 15 Hz. It is evident that with increasing frequency and volumetric flow, the flow velocity increases, mixing increases, and the boundary layer penetrates and becomes thinner. As a result, eddy currents form, increasing heat transfer, which in turn increases convection. The Nusselt number, which represents the convection function, increases with increasing transfer. The increase in the improvement percentages of the heat transfer coefficient at frequencies 5 and 10 Hz, according to the adopted volume flows, was as follows: (7.67%, 11.07%, 12.75%, 12.95%) and (11.92%, 17.08%, 17.79%, 19.73%) respectively. The highest increase in the improvement percentage was 14.05%, 17.85%, 18.73% and 23.40% at frequencies of 15 Hz, as shown in Figure 9.

Our findings and those published by Li et al. [35] have been quantitatively compared. This comparison draws attention to the two research’s similarities and differences. Vibration caused an overall increase in the heat transfer coefficient in Li's experiments: for the liquid phase, this increase ranged from roughly 1.9% to 11.7%, with an average enhancement of about 6.8%; for the gas phase, it ranged from roughly 3.0% to 16.8%, with an average of roughly 9.9%. These results show the degree of agreement or improvement in thermal performance when compared to previously published data and offer a clear reference for positioning our findings.

The improvement in the dimensionless heat transfer coefficient (Nusselt number) is represented by the percentage. According to the improvement ratio law, these percentages not only show theoretical improvement but also improve operating margins in a scientific manner. The difference in heat transfer improvement with higher vibration is what causes this improvement.

By assessing the combined impact of vibration frequency and volumetric flow rate on the thermal performance of the water-air heat exchanger, this study offers a novel approach in comparison to earlier research, connecting improved heat transfer to mixing and a decrease in the thickness of the boundary layer. Additionally, it offers exact quantitative measures of the increase in heat transmission, which can reach up to 23.4% and 12.99%, respectively—findings not addressed in earlier research.

An empirical correlation based on an approximation (regression analysis) of experimental data was obtained in order to quantitatively characterize the impact of mechanical vibration on convective heat transfer. This is the suggested relationship:

where,

$N u$ is the Nusselt number;

$R e$ is the Reynolds number;

$Pr$ is the Prandtl number;

$f$ is the vibration frequency (Hz);

$C, a, b$, and $c$ are empirical coefficients determined by nonlinear regression.

Based on the processing of the experimental data from this study, the following coefficient values were obtained: $C$ = 0.018, $a$ = 0.84, $b$ = 0.36, $c$ =0.12.

An increase in vibration frequency results in a higher Nusselt number, or more intense heat transfer, if the exponent $c$ is positive. Increased flow mixing and disruption of the thermal boundary layer provide an explanation for this. The model's validity is confirmed by the suggested correlation, which shows good agreement with experimental results: the average relative error is 7.11% and the determination coefficient $R^2$ = 0.94.

The correlation is applicable in the following parameter ranges: 4000 $\leq$ $Re$ $\leq$ 18000 ; $Pr$ $\approx$ 0.7 (air); Volumetric flow: 1.5–4.5 LPM; 0 $\leq$ $f$ $\leq$ 25 Hz.

The suggested association predicts greater Nusselt numbers in the presence of vibration as opposed to the traditional Sieder-Tate correlation, which disregards its impact. This demonstrates that vibration improves heat transmission by enhancing turbulent disturbances and decreasing the thickness of the thermal barrier layer.

This study investigates how vibration and volumetric flow rate can enhance a composite heat exchanger’s thermal performance, with an emphasis on the water-inside and air-sides.

1. The investigation showed that as vibration frequency and volumetric fluid flow rate increase, the composite heat exchanger’s thermal performance greatly improves.

2. The approach was effective on both sides of the exchanger, as evidenced by the maximum heat transfer increment of 23.4% on the water-inside and 12.99% on the air-side.

3. By interfering with the uniform water flow, vibration increases forced convection heat exchange by reducing the thickness of the boundary layer and promoting layer mixing.

4. The findings demonstrate that when vibration and a higher flow rate are combined, the effects are better than when each component is used separately.

5. Compared to other methods for enhancing heat transmission, the vibration-based approach is easy to use and effective.

6. Despite the encouraging outcomes, there are still few real-world uses for this method, which highlights the need for more research to assess the impact of vibration under various operating circumstances.

7. Future study should broaden its focus to include precise heat exchange measurements under industrial operating settings, examination of the impact of higher frequencies, and evaluation of thermal performance in multi-layer systems.