Research on the Heat Dissipation in Aviation-Integrated Communication Equipment Based on Graphene Films

Abstract

Aviation-integrated communication equipment is integral to modern aircraft to ensure its performance and safety. The heat dissipation problems of equipment have become increasingly prominent for the high electronic integration and system power consumption. To solve the above problem, the heat dissipation performance of aviation-integrated communication equipment based on graphene films is deeply studied. This paper establishes a three-dimensional model of aviation-integrated communication equipment to simulate the distribution of temperature fields. The influence between aluminum alloy and graphene films on the surface of magnesium alloy on the heat dissipation performance of aviation-integrated communication equipment is studied. The simulation results show that the heat balance time of the equipment using graphene films on the surface of magnesium alloy is reduced from 3600 s to 800 s, representing an approximately 77.78% improvement; the measured equipment exhibited a reduction in its overall thermal equilibrium temperature, decreasing from 68.1 °C to 66.3 °C, representing an improvement of approximately 2.64%.

1. Introduction

With the development of China’s civil aviation [1] and civil aircraft industry [2] in recent years, avionics equipment [3] has become an essential component of modern aviation, playing a crucial role in the performance and safety of aircraft [4]. To accomplish flight, all the essential independent communication equipment [5] must occupy specific places in the cabin, including short-wave communication, ultra-short-wave communication [6], satellite communication [7], and data link [8], which leads to the overload of cabin equipment space and carrying capacity. Consequently, aviation-integrated communication equipment [9,10] emerged as the times required. The equipment integrates self-organized network communication links [11], 4G/5G public network communication links [12], real-time kinematic (RTK) differential high-precision positioning links [13], BeiDou third-generation short message communication links [14], aviation automatic dependent surveillance-broadcast (ADS-B) communication links [15], integrated control centers, and a power adaptation module. However, high electronic integration, high system power consumption, and prolonged continuous running result in the increasingly severe issue of radiating heat, which is critical to regular operation and lifespan [16]. Thus, conducting efficient heat dissipation research for highly integrated aviation communication equipment is vital.

In 2018 [17], Li J. et al. stabilized graphene layers by intercalating laponite between them; this intercalation method offers an alternative method for the dispersion of graphene layers. In 2019, high-performance polymer composite films with a combination of natural rubber/graphene nanoplatelet (NR/GNPs) composites and NR/boron nitride (NR/BN) composites were fabricated by Feng C.P. et al. and proved to be superior thermal interface material [18]. In 2020, Fan D. et al. proposed a composite foil with a sandwich structure of graphite–silver–polyimide that exhibited high thermal conductivity and reduced the local high temperature of the surface [19]. In 2020, Li W. et al. developed two types of high thermal conductive flexible phase change materials (FPCMs) into film morphology and added the graphene film to enhance transverse heat transfer [20,21]. In 2021, Dongsheng Yang et al. presented a flexible composite material based on nano-efficient cooling methods; the results show that the optimized equipment heat source temperature can be reduced by up to 8.5 °C [22]. In 2021, Yu Chen et al. reported the facile preparation of highly thermally conductive and electrically insulating poly(p-phenylene benzobisoxazole) nanofiber (PBONF) composites by incorporating a low-weight fraction of functionalized boron nitride nanosheets (BNNSs); the 5G equipment and high-power density electronic devices with the nanocomposite paper shows excellent heat dissipation performance [23]. With extraordinary heat dissipation performance, alloy graphene is increasingly popular. In 2018, Le Zhang et al. prepared aluminum/graphene composites with enhanced heat-dissipation properties by the in situ reduction of graphene oxide on aluminum particles; the enhancement of 9.1% in specific heat capacity was achieved with only 0.3% graphene addition into pure Al. In 2022 [24], Hao-liang Li et al. reduced GO/polyimide carbon (rGO/PI-carbon) films were prepared by a one-pot “grafting-welding” strategy and exhibited an increase in the in-plane thermal conductivity of 48.92% compared with the rGO film. In 2023 [25], Shibo Wang et al. adopted the high thermal conductivity graphene paper to directionally transfer the heat produced in the battery to the compact aluminum fin; the maximum temperature of the battery in UAV can be reduced by 34.00%. In 2023 [26], the research on graphene aerogel composite phase change materials indicates that the heat dissipation enhancement of those composite materials can reach 220.8%. In 2024 [27], Yi Shen Lim explored the remarkable enhancement of light-emitting diode (LED) cooling through nucleate boiling using hybrid coatings of graphene-nanoplatelets (GNP) and carbon nanotubes (CNT), which exhibited a maximum temperature drop of 20.7 °C and an enhancement up to 1212%. Nevertheless, research on applying alloy graphene in aviation-integrated communication equipment is still lacking [28].

A three-dimensional model structure is constructed to study the heat-dissipation performance of aviation-integrated communication equipment, and the temperature distribution of the heat-dissipation system is simulated. The influence between aluminum alloy and graphene films on the surface of magnesium alloy on the heat dissipation performance of aviation-integrated communication equipment is studied. This paper aims to compare the heat balance time and overall thermal equilibrium temperature between traditional aluminum alloy material and graphene films on the surface of magnesium alloy material so as to demonstrate the potential for real applications using the new materials.

2. Three-Dimensional Modeling of Aviation-Integrated Communication Equipment

In this section, we present the 3D modeling approach used to analyze the thermal performance of aviation-integrated communication equipment. The detailed composition and mechanical properties of the equipment are discussed to provide a comprehensive understanding of the system.

2.1. Equipment Composition

Aviation-integrated communication equipment comprises self-organized network communication links, 4G/5G public network communication links, RTK differential high-precision positioning links, Beidou third-generation short message communication links, aviation ADS-B broadcast communication links, integrated control centers, and power adaptation parts. The equipment composition is shown in Figure 1.

2.2. Mechanical Property

Considering the structural strength and thermal conduction path of aviation equipment, the aviation-integrated communication equipment adopts a modular structure. The structure is mainly composed of three modules, 0-10, 0-20, and 0-30, which cover the top of the plate and the backplane and are connected by the screw into a whole. The 2D diagram of the mechanical structure is shown in Figure 2, and the 3D modeling is shown in Figure 3. The 0-10 module includes an aviation ADS-B broadcast communication link; the 0-20 module includes an RTK differential high-precision positioning link, integrated control center module, and power adapter module; and the 0-30 module consists of a self-organized network communication link, a 4G/5G public network communication link, and a Beidou third-generation short message communication link.

①

Shape size: (216.0 ± 1.0) mm × (160.0 ± 1.0) mm × (83.3 ± 1.0) mm;

②

Equipment power dissipation: 28 V/82.5 V (peak value), 41.5 W (mean value), power dissipation is shown in

Table 1. Aviation-integrated communication equipment Power Dissipation Calculation.

Module	Static Power Dissipation (W)	Peak Value Power Dissipation (W)
Self-organizing network communication module	2.0	5.0
4G/5G public network communication module	1.0	5.0
RTK differential high-precision positioning module	3.0	3.0
BeiDou-3 short message communication module	2.1	15.0
Aviation ADS-B broadcast communication module	20.1	33.0
Integrated control module	5.0	5.0
Power efficiency	80.00%	80.00%
Overall unit power dissipation	41.5	82.5

.

3. Mathematical Modeling

The mathematical modeling of aviation-integrated communication equipment is crucial to understanding its thermal behavior and optimizing its heat dissipation performance. In this section, we outline the general conditions and parameters necessary for constructing the model.

3.1. Model Condition

Aviation-integrated communication equipment has high electronic integration, light structure weight, and high system power consumption, which requires a long time. The normal working environment modeling parameters of aviation-integrated communication equipment are as follows:

①

Working mode: prolonged continuous running;

②

Working situation: initial temperature 25 °C, working temperature range 25~40 °C;

③

Installation mode: the terminal is installed in contact with the cabin flat, and temperature control of the installation surface is constant at 40 °C;

④

Heat dissipation mode: convection heart dissipation mainly, radiation heat transfer auxiliary, as is shown in Figure 4;

⑤

Surface operation: increasing heat dissipation with black anodization, heat radiation rates = 0.88;

⑥

Working heat consumption: the average thermal power consumption of the equipment is 41.5 W.

3.2. Model Parameters

(1)

Aluminum alloy parameters

The structure of aviation-integrated communication equipment is mainly made of aluminum alloy 2A12, with the peculiarities of high strength and stiffness as well as good corrosion resistance, fracture toughness, and anti-fatigue properties [29]; it is one of the most widely used structural materials in the aerospace industry. Silicone thermal conductive pad [30] is provided with merit viscosity, flexibility, compressibility, and thermal conductivity; hence, the heat dissipation effect can be increased after enabling sufficient contact between electronics and the radiating fin with the silicone thermal conductive pad. Fiberglass [31] and plastic capsulation [32] show the benefits of light weight, strength, corrosion resistance, thermal performance, designability, and processability, which have now been widely used in printed circuit board [33] materials. The parameters of aluminum alloy aviation-integrated communication equipment structure material are defined in

Table 2. Aluminum alloy aviation-integrated communication equipment structure material parameters.

Name of Material	Specific Heat Capacity (J·(kg·k)−1)	Thermal Conductivity (W·(m·k)−1)		Density (g/cm3)
Aluminum AL-2A12	920	121		2.78
Fiberglass Fr4	1150	23.5	X direction	1.85
		0.32	Y direction
		23.5	Z direction
Plastic capsulation	850	5		1.9
Silicone thermal conductive pad	1500	4		1.0

.

(2)

Graphene films on the surface of magnesium alloy parameters

Magnesium alloy has the advantages of low density, moderate strength, and an easy process. Magnesium alloys [34] have a particular gap in thermal conductivity compared to aluminum alloys [35]. Thus, it is essential to assist magnesium alloys with superior thermal conductivity materials. The thermal conductivity of graphene is currently the highest among known materials. In 2008, the Balandin research group [36] first measured the thermal conductivity of single-layer graphene using Raman spectroscopy. Observation shows that the highest thermal conductivity of graphene can reach 5300 W/m/K, which is the highest thermal conductivity value of any known material; the study attracts many researchers. Graphene has a certain corrosion resistance, and graphene is corrosion resistant by coating as a protective film on the surface of a magnesium alloy. The study is based on aluminum alloy; a graphene membrane is covered on the surface, thereby reducing the weight and improving the heat dissipation performance of aviation-integrated communication equipment. The main parameters are defined in

Table 3. Aviation-integrated communication equipment of graphene films on the surface of magnesium alloy structure material parameters.

Material Name	Specific Heat Capacity (J·(kg·k)−1)	Thermal Conductivity (W·(m·k)−1)		Density (g/cm3)
Magnesium Alloy	245	154		1.73
Glass Fiber Fr4	1150	23.5	X direction	1.85
		0.32	Y direction
		23.5	Z direction
Plastic Packaging	850	5		1.9
Graphene Membrane	750	5000	X direction	1.05
		50	Y direction
		5000	Z direction
Thermal Pad	1500	4		1.0

.

(3)

Heat source parameters

Table 4. Heat source parameters of the main power devices in aluminum alloy aviation-integrated communication equipment.

Component Name	Thermal Resistance (°C/W)	Average Heat Consumption (W)	Allowable Operating Temperature (°C)	Quantity
0-10-DCDC	/	10	85	1
0-10-FPGA	/	3	85	1
0-10-HT1H	/	2	125	1
0-10-TPS54527	5.2	0.37	125	1
0-20-PAF	6.5	0.1	125	1
0-20-PAR	/	0.015	125	1
0-20-CLOCK	6.9	1.5	125	1
0-20-SoC	3.4	6.5	125	1
0-20-DDR3	6.5	2.1	125	2
0-20-AD	0.6	1.4	125	1
0-20-DCDC	25.7	1	125	1
0-30-CX6672	/	5	125	1
0-30-TPS54527	5.2	0.67	125	1
0-30-RM500Q	/	4.5	125	1
0-30-TPS54527	5.2	0.5	125	1
0-30-RD05W3035	/	0.55	125	1
0-30-TPS54527	5.2	0.15	125	1

shows the heat source parameters of the primary power devices in aviation-integrated communication equipment; the average total heat consumption is 41.5 W.

3.3. Model Development

(1)

Rationale

According to the laws of physics, the generalized nonlinear heat balance matrix equation is as follows:

$$[C(T)]\left\{\stackrel{•}{T}\right\}+[K(T)]\left\{T\right\}=[Q(T)]$$

(1)

where {T} is the temperature matrix; C is the specific heat matrix; K is the heat conduction matrix; Q is the heat flux load vector. When there is a temperature gradient inside an object, heat will be transferred from the high-temperature to the low-temperature part. When objects of different temperatures come into contact, heat will also be transferred from the high-temperature object to the low-temperature object. This type of heat transfer is called heat conduction. Fourier’s law can describe heat conduction in a general form:

$$\overrightarrow{q}=\frac{Q}{A}=-k\nabla t=-k\left(\frac{\partial t}{\partial x}\overrightarrow{i}+\frac{\partial t}{\partial y}\overrightarrow{j}+\frac{\partial t}{\partial z}\overrightarrow{k}\right)$$

(2)

Thermal convection is the thermal phenomenon in which heat is carried from one part of a fluid to another due to relative motion between different parts of the fluid at different temperatures. Convective heat transfer is described by the Newton cooling formula; the general form is normally described as $q=Q/A=h\Delta t$. In the equation, h is the convective heat transfer coefficient, a physical quantity reflecting the strength of convective heat transfer. Thermal radiation is the process of transmitting energy through electromagnetic waves (or photon flows), and the radiation energy of an object is $Q=\epsilon A_s\sigma T^4$. In this formula, $\epsilon$ is emissivity, $A_s$ is the surface area, T is the absolute temperature, and $\sigma$ is the Stephen–Boltzmann constant.

(2)

Simulation Model

Ansys Workbench models the thermal simulation of aviation-integrated communication equipment, and the Ansys(2020) Solver of Mechanical analyzes the structure and thermal. The simulation model adopts a regular tetrahedral mesh method for mesh division and applies encryption processing to a crucial local area grid. The total number of grid elements is 174,000, and the total number of nodes is 414,000. The finite element thermal analysis model is shown in Figure 5.

The thermal simulation model, as shown in Figure 5, demonstrates the detailed 3D structure used for analyzing heat dissipation. The model includes key components and their connections, which are crucial for understanding the thermal behavior of the equipment.

4. Results and Discussion

This section presents the simulation results and provides an in-depth analysis of the heat dissipation performance of the aviation-integrated communication equipment. The discussion focuses on comparing the traditional aluminum alloy and the graphene-enhanced magnesium alloy.

4.1. Aluminum Alloy Simulation Results and Discussion

The initial temperature of the thermal simulation of aviation-integrated communication equipment is set at 25 °C, and the simulation time is set for 90 min. The results of the mild junction temperature of the main components of aluminum alloy aviation-integrated communication equipment are shown in

Table 5. Analysis of junction temperature of main components in aluminum alloy aviation-integrated communication equipment.

Component Name	Thermal Resistance (°C/W)	Average Heat Consumption/W	Component Shell Temperature (°C)	Component Junction Temperature (°C)
0-10-DCDC	/	10	43.0	/
0-10-FPGA	/	3	50.8	/
0-10-HT1H	/	2	50.2	/
0-10-TPS54527	5.2	0.37	57.2	59.2
0-20-PAF	6.5	0.1	54.0	54.7
0-20-PAR	35	0.015	49.9	50.4
0-20-CLOCK	6.9	1.5	61.3	71.7
0-20-SoC	3.4	6.5	65.3	87.4
0-20-DDR3	6.5	2.1	59.4	73.1
0-20-AD	0.6	1.4	65.9	66.7
0-20-DCDC	7.4	1	56.0	73.4
0-30-CX6672	/	5	53.7	/
0-30-TPS54527	5.2	0.67	68.1	71.6
0-30-RM500Q	/	4.5	57.2	/
0-30-TPS54527	5.2	0.5	67.2	69.8
0-30-RD05W3035	/	0.55	47.6	/
0-30-TPS54527	5.2	0.15	49.2	50.0

. The thermal balance temperature of 0-10, 0-20, and 0-30 aluminum alloy aviation-integrated communication equipment is shown in

Table 6. Aluminum alloy aviation-integrated communication equipment Module Temperature Cloud Diagrams.

Component Name	Thermal Equilibrium Temperature/°C	Temperature Cloud Graph	Temperature Change Curve
0-10	52.7
0-20	61.4
0-30	55.1
Equipment	68.1

.

According to the simulation results of Table 5 and Table 6, it is known that the aluminum alloy aviation-integrated communication equipment works continuously for about 3600 s, and the heat equilibrium temperature of the equipment is 68.1 degrees; the heat equilibrium temperature of the 0-10 module is 52.7 degrees; the thermal equilibrium temperature of 0-20 module is 61.4 degrees; the thermal equilibrium temperature of 0-30 module is 55.1 degrees; the maximum temperature of the central heating components in the module is SOC chip, and the maximum thermal equilibrium junction temperature of SOC chip is 87.4 °C. In summary, the mass density of aluminum alloy 2A12 is high, the overall thermal balance time of the equipment is relatively long, some devices have high heat generation, and the temperature conduction effect is not good.

4.2. Magnesium Alloy Simulation Results and Discussion

The initial temperature of the thermal simulation of aviation-integrated communication equipment is set at 25 °C, and the simulation time is set for 90 min. The results of the mild junction temperature of the main components of magnesium alloy aviation-integrated communication equipment are shown in

Table 7. Analysis of junction temperature of main components in magnesium alloy aviation-integrated communication equipment.

Component Name	Thermal Resistance (°C/W)	Average Heat Consumption/W	Component Shell Temperature (°C)	Component Junction Temperature (°C)
0-10-DCDC	/	10	42.4	/
0-10-FPGA	/	3	50.7	/
0-10-HT1H	/	2	49.8	/
0-10-TPS54527	5.2	0.37	55.3	57.3
0-20-PAF	6.5	0.1	53.8	54.5
0-20-PAR	35	0.015	49.8	50.3
0-20-CLOCK	6.9	1.5	60.6	71
0-20-SoC	3.4	6.5	63	85.1
0-20-DDR3	6.5	2.1	58.2	71.9
0-20-AD	0.6	1.4	65.3	66.1
0-20-DCDC	7.4	1	54.4	61.8
0-30-CX6672	/	5	52.9	/
0-30-TPS54527	5.2	0.67	66.8	70.3
0-30-RM500Q	/	4.5	46.9	/
0-30-TPS54527	5.2	0.15	48.8	49.6
0-30-RD05W3035	/	0.55	47.6	/
0-30-TPS54527	5.2	0.15	49.2	50.0

. The thermal balance temperature of 0-10, 0-20, and 0-30 magnesium alloy aviation-integrated communication equipment is shown in

Table 8. Magnesium alloy aviation-integrated communication equipment Module Temperature Cloud Diagrams.

Component Name	Thermal Equilibrium Temperature/°C	Temperature Cloud Graph	Temperature Change Curve
0-10	53.7
0-20	61.6
0-30	56.0
Equipment	67.2

.

According to the simulation results of Table 7 and Table 8, it is known that the magnesium alloy aviation-integrated communication equipment works continuously for about 5400 s, and the heat equilibrium temperature of the equipment is 67.2 degrees; the heat equilibrium temperature of the 0-10 module is 53.7 degrees, the thermal equilibrium temperature of 0-20 module is 61.6 degrees, the thermal equilibrium temperature of 0-30 module is 56.0 degrees, the maximum temperature of the central heating components in the module is SOC chip, and the maximum thermal equilibrium junction temperature of SOC chip is 85.1 °C. In summary, the mass density of magnesium alloy is low, the overall thermal balance time of the equipment is particularly long, some devices have high heat generation, and the temperature conduction effect is still not good.

4.3. Graphene Films on the Surface of Magnesium Alloy Simulation Results and Discussion

The initial temperature of the thermal simulation of aviation-integrated communication equipment is set at 25 °C, and the simulation time is set for 90 min. The shell temperature and junction temperature results of the main components of graphene films on the surface of magnesium alloy aviation-integrated communication equipment are shown in

Table 9. Aviation-integrated communication equipment of graphene films on the surface of magnesium alloy main components analysis junction temperature.

Component Name	Thermal Resistance (°C/W)	Average Heat Consumption/W	Component Shell Temperature (°C)	Component Junction Temperature (°C)
0-10-DCDC	/	10	40.7	/
0-10-FPGA	/	3	44.2	/
0-10-HT1H	/	2	47.9	/
0-10-TPS54527	5.2	0.37	53.9	55.9
0-20-PAF	6.5	0.1	45.2	45.9
0-20-PAR	35	0.015	41.9	42.4
0-20-CLOCK	6.9	1.5	45.9	56.3
0-20-SoC	3.4	6.5	48.3	70.4
0-20-DDR3	6.5	2.1	50.7	64.4
0-20-AD	0.6	1.4	53.6	54.4
0-20-DCDC	7.4	1	50.1	57.5
0-30-CX6672	/	5	46.6	/
0-30-TPS54527	5.2	0.67	66.3	69.8
0-30-RM500Q	/	4.5	47.3	/
0-30-TPS54527	5.2	0.5	60.5	63.1
0-30-RD05W3035	/	0.55	41.3	/
0-30-TPS54527	5.2	0.15	44.1	44.9

, and the thermal balance temperature cloud map of 0-10, 0-20, and 0-30 modules of graphene films on the surface of magnesium alloy aviation-integrated communication equipment is shown in

Table 10. Aviation-integrated communication equipment of graphene films on the surface of magnesium alloy temperature cloud diagrams.

Component Name	Thermal Equilibrium Temperature/°C	Temperature Cloud Graph	Temperature Change Curve
0-10	45.6
0-20	48.3
0-30	45.0
Equipment	66.3

.

According to the simulation results of Table 9 and Table 10, magnesium alloy + graphene membrane aviation-integrated communication equipment works continuously for about 800 s and gradually tends toward the thermal equilibrium state. The heat balance temperature of the equipment is 66.3 degrees. The thermal balance temperature of the 0-10 module is 45.6 degrees; 0-20 is 48.3 degrees. The thermal balance temperature of the SOC chip with the highest temperature of the central heating device in the module is 70.4 degrees. The thermal balance temperature of the 0-30 module is 45 degrees. In summary, with the magnesium alloy + graphene film as the structural material of the equipment, the weight of aviation-integrated communication equipment is 0.43 kg less than aluminum alloy, reducing the load burden in the cabin. The thermal balance time is decreased from 3600 s to 800 s, with a reduced thermal equilibrium temperature for all single plates and devices, improving the heat dissipation performance of the equipment. Moreover, the requirements for the needed mechanical strength when engineering aviation communication equipment were met, equipment weight was reduced, and the heat dissipation performance of the equipment was improved.

5. Conclusions and Future Work

Graphene is known for having the highest thermal conductivity among most materials. It has promising applications in various fields, including electronic devices, information technology, national defense, and the military industry. This study introduces graphene films on the surface of magnesium alloy in aviation-integrated communication equipment. This material offers significant advantages in terms of structural weight and heat dissipation performance. The succeeding work considers the design for producing a prototype, which aims to bring new materials, such as graphene films on the surface of magnesium alloy, to practical engineering applications. This will improve the overall mechanical performance of comprehensive aviation communication equipment.