Category: 5. Surface Transportation Noise and Vibration Sources and Control

Many of the same noise problems exist in passenger ships as in surface transportation vehicles and aircraft. Airborne and structure‐borne paths from noise and vibration sources can be of similar and sometimes of equal concern during different ship operations. The main sources include the power plant machinery and the propulsion units including screws and propellers. Figure…

14.4.1 Wheel–Rail Interaction Noise Noise produced by wheel–rail interaction continues to be of concern in railway operations. Many studies have been conducted on wheel–rail interaction noise. Most of the studies have involved various measurement approaches [77–85]. Main wheel–rail sources include (i) rolling noise, which is caused by small‐scale vertical profile irregularities (roughness) of wheel and…

14.3.1 Automobiles and Trucks The interior noise in the occupied spaces of automobiles, busses, and trucks is mainly caused by the engine, exhaust, transmission, power train, tire/road interaction, and wind/structure interaction. With automobiles, trucks, and busses, structure‐borne noise usually tends to be dominant below about 400–500 Hz, while airborne noise from tire/road interaction and airflow/structure interaction (wind…

Brake noise has been recognized as a problem since the mid‐1930s. Research was initially conducted on drum brakes, but recent work has concentrated on disk brakes since they are now widely used on cars and trucks. The disk is bolted to the wheel and axle and thus rotates at the same speed as the wheel.…

Transmissions and gearbox systems are used in cars, trucks, and busses to transmit the mechanical power produced by the engine to the wheels. Similar transmission systems are used in propeller aircraft to transmit power to the propeller(s) from the engine(s) or turbine(s). Transmission gearboxes are also used in some railroad systems and ships. Some modern…

The interaction of the flow around a vehicle with the vehicle body structure gives rise to sound generation and noise problems both inside and outside the vehicle. Turbulent boundary layer fluctuations on the vehicle exterior can result in sound generation. The pressure fluctuations also cause structural vibration, which in turn results in sound radiated both…

In most developed and developing countries, vehicle traffic is the main contributor to community noise. Aircraft noise is a lesser problem since it mostly affects small areas of urban communities that are located near to major airports. The substantial increase in road vehicle traffic in Europe, North America, Japan, and other countries suggests that road…

With each intake stroke, ICE engine noise is generated by an unsteady airflow produced by the volume of air that each cylinder draws in. Ducted sources are found in many different mechanical systems. Common ducted‐source systems include engines and mufflers (also known as silencers), fans, and air‐moving devices (including flow ducts and fluid machines and…

Although hybrid vehicles (HVs), which partially use relatively quiet electric motors, are increasing in use, the internal combustion engine (ICE) remains a major source of noise in transportation and industry. ICE intake and exhaust noise can be effectively silenced [4]. The noise radiated by vibrating engine surfaces, however, is more difficult to control. In gasoline engines a fuel–air mixture…

In cars, trucks, and busses, major power plant noise sources include gasoline and diesel engines, cooling fans, gearboxes and transmissions, and inlet and exhaust systems. Other major sources include tire/road interaction noise and vibration and aerodynamic noise caused by flow over the vehicles [1]. (See Figure 14.1) Although vehicle noise and vibration have been reduced over…