Auslegung von SCR-Systemen zur Stickoxidreduktion bei Dieselmotoren

Experimental determination of the aero-acoustic properties of an in-duct flexible Plate

“…It is seen that when the pressure loss coefficient is low the reflection coefficient elements (1,1) and (2,2) are small while the transmission elements (1,2) and (2,1) are close to unity. With increasing pressure loss the balance changes and a larger part of the incoming travelling waves are reflected.…”

“…The two-port is defined such as the positive travelling wave direction is outwards from it. From the definition it is seen that the elements (1,1) and (2,2) of the scattering matrix can be interpreted as reflection coefficients seen from the upstream and downstream side respectively, while the remaining two elements are the corresponding transmission coefficients.…”

“…One application is diesel exhaust after-treatment systems using selective catalytic reduction (SCR), where an additive is injected under low pressure into an exhaust stream. 1,2 A photograph of the test object installed in the test rig is seen in Figure 1. The mixer consists of a single triangularly shaped plate, inserted at an angle of 32 degrees, and fixed at the base in a circular duct.…”

Ceramic foam substrates for automotive catalyst applications: fluid mechanic analysis

“…As a means to achieve uniform flow distribution upstream of DPFs the use of helical-type flow elements is proposed (Gaiser et al 2003;Oesterle et al 2004). Similar mixing devices have also been proposed to achieve uniform flow distribution and proper mixing upstream of selective catalytic reduction (SCR) catalysts (Kaiser and Rusch 2007), where a small amount of liquid urea is injected in the exhaust line to help the reduction of nitrogen oxides. Initial investigations on the potential of achieving uniform flow distribution upstream of DPFs and SCR catalysts by using foam substrates upstream of these devices have already been performed (Dimopoulos et al 2007).…”