## 1 Introduction  
Tire acoustic cavity resonance (TACR) noise is well known for its large effect on vehicle ride comfort. Researchers have found a distinct peak in the frequency spectrum of interior noise that coincides with the natural frequency of the tire acoustic cavity [1, 2, 3]. Since the importance of this resonance phenomenon was discovered, efforts have been made to reveal the vibration and acoustic properties of the tire acoustic cavity's coupled structure [4, 5, 6, 7]. In respect to noise reduction, previous studies mostly used sound absorbing materials, resonators or damping structures to suppress the resonance [8, 9, 10]. [PERSON] [11] found that filling the tire cavity with mineral fibers could reduce the noise sound pressure level by 20 dB, while [PERSON] [12] studied the noise reduction effects of various sound-absorbing materials including fabric fibers and aluminum foam. [PERSON] [13] used a Helmholtz resonator to dissipate the resonance energy and applied the device to industrial models.  
The wheel stands first in the propagation path of TACR energy into the car cabin and is highly designable. Therefore, the wheel has high potential for resonance noise suppression. [PERSON] et al. [14] considered the wheel's optimal design as the most economical and practical method to suppress the propagation of TACR noise. Since then, research on modifying wheel structures has appeared. [PERSON] et al. [15] studied the influence of fiber-reinforced composite wheels on tire cavity noise, [PERSON] et al. [16] used the inner trim to reduce the resonance. However, up to now, there has not yet been a complete wheel design theory and method to suppress the energy transmission.  
TACR energy propagates from the tire cavity to the wheel, ultimately reaching the car cabin. As for the investigation of the energy propagation in a structure, the structural power flow method is very helpful [17; 18; 19] and can be used to describe the vibration energy distribution. [PERSON] et al. [20] studied the power flow of a coupled cylindrical shell-plate structure with four types of coupling springs. [PERSON] et al. [21] calculated the power flow of infinitely long beams and slab structures under force and torque excitation. In recent years, the research on the structural power flow method in engineering design has increased and expanded to various areas [22]. [PERSON] et al. [23] used this method to evaluate the energy in locally resonant metamaterials. However, there is no previous research on the application of the power flow method for investigating the energy dissipation of TACR in the propagation process.  
In this paper, a mathematically fitting load model arising from TACR energy acting on the rim is put forward, which is first based on experimental and simulation results. The power flow method is applied to calculate the resonance energy transmission characteristics in different aluminum alloy wheels. Then, the effects of structure damping and the wheel spoke number are also studied. The path of this work's technique is shown in Figure 1. These works may help further design the wheel structure to reduce the propagation of TACR energy into the cabin.  
Figure 1: Flowchart of the technique’s path.