Smooth Ride for Better Products
Flow phenomena touch us daily - for example, when we pour a drink or enjoy a ride through fresh air in a convertible. Everywhere we go, we're in touch with “fluids in motion”. It's no difference with state-of-the-art products from Bosch. From the development of fuel injection systems to new wiper blades, everything depends on understanding fluid mechanics.
“Panta rhei - everything flows” is the famous dictum of the Greek philosopher Heraclitus. The realization that flow is everywhere is also a fact of life for researchers and engineers at Bosch: Mastery of the fluid mechanics of air, water, fuel and hydraulic oil is becoming ever more important as a core competence of Bosch research. There's hardly a product whose function isn't somehow affected by flow phenomena. Just one example: Precisely defined air currents protect generators and electric power tools, such as drills, against overheating.
When it comes to liquids like gasoline or diesel fuels, understanding and applying fluid mechanics to carburetion and fuel injection are indispensable to fuel economy. However, the flow of these essentially homogeneous media - whether air or liquid - is ordinarily invisible. Nevertheless, ingenious test methods and modern laser techniques make it possible to visualize the behavior of these flows at corners or edges within an injection nozzle or power drill. Bosch scientists use such techniques to understand the intricacies of flow phenomena.
In this endeavor they are getting amazing support from nature. Due to the laws of physics, extensive experiments in fluid mechanics can be conducted on large-scale models, such as an enlarged injection valve. The physical behavior of fluids remains the same, so even microstructures of the smallest components can be studied in transparent models that are often enlarged by a factor of 50 or more.
In combustion engines, an essential precondition for fuel-efficient and low-emission operation is that the injected quantity of fuel be precisely adjusted to the amount of inducted air. A hot-film air-mass meter (HFM) used in microsystems technology provides the required signal for the valve timing system. But when the throttle valve is wide open, resonance effects in the inducted air can “confuse” the mass sensor: Air not only flows toward the engine - some of it also flows in reverse.
Bosch researchers use laboratory experiments and computer simulations to determine the optimum position for the HFM, with its barely pea-sized sensing element within the intake pipe, in order to ensure that the measured values correspond to the air mass actually inducted.
When it comes to liquids like gasoline or diesel fuels, understanding and applying fluid mechanics to carburetion and fuel injection are indispensable to fuel economy. However, the flow of these essentially homogeneous media - whether air or liquid - is ordinarily invisible. Nevertheless, ingenious test methods and modern laser techniques make it possible to visualize the behavior of these flows at corners or edges within an injection nozzle or power drill. Bosch scientists use such techniques to understand the intricacies of flow phenomena.
In this endeavor they are getting amazing support from nature. Due to the laws of physics, extensive experiments in fluid mechanics can be conducted on large-scale models, such as an enlarged injection valve. The physical behavior of fluids remains the same, so even microstructures of the smallest components can be studied in transparent models that are often enlarged by a factor of 50 or more.
In combustion engines, an essential precondition for fuel-efficient and low-emission operation is that the injected quantity of fuel be precisely adjusted to the amount of inducted air. A hot-film air-mass meter (HFM) used in microsystems technology provides the required signal for the valve timing system. But when the throttle valve is wide open, resonance effects in the inducted air can “confuse” the mass sensor: Air not only flows toward the engine - some of it also flows in reverse.
Bosch researchers use laboratory experiments and computer simulations to determine the optimum position for the HFM, with its barely pea-sized sensing element within the intake pipe, in order to ensure that the measured values correspond to the air mass actually inducted.
Laser light reveals flows and turbulences around the air-mass sensor.
