Browse Prior Art Database

Reducing exhaust gas backpressure

IP.com Disclosure Number: IPCOM000171432D
Publication Date: 2008-Jun-09
Document File: 2 page(s) / 44K

Publishing Venue

The IP.com Prior Art Database

Abstract

Abstract In exhaust gas systems for automotive vehicles, noise-efficient mufflers and particle filters increase the pressure in the exhaust manifold. The engine must therefore produce more power to force the exhaust gases out of the exhaust gas system. This in turn reduces the efficiency of the engine. It is therefore desirable to have a low back pressure in the exhaust gas system. According to the invention, the exhaust system comprises a funnel-shaped air duct having a forward wide end for admitting oncoming outside air into the duct during vehicle travel and a rearward narrow end for discharging the air into a tail portion of the exhaust gas system. The velocity of the air increases when the air is forced through the narrowing duct. The high velocity air will be injected into a tail portion of the exhaust system from a narrow end of the air duct. The injected high velocity air will entrain and increase the flow of slower velocity exhaust gases entering the tail portion. The result is a decreasing back pressure upstream in the exhaust system to thereby improve engine efficiency

This text was extracted from a Microsoft Word document.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 71% of the total text.

Reducing exhaust gas backpressure

Noise-efficient mufflers and particle filters increase the pressure in the exhaust manifold of an internal combustion engine. The engine must therefore produce more power to force the exhaust gases out of the exhaust gas system. This in turn reduces the efficiency of the engine. It is therefore desirable to have a low back pressure in the exhaust gas system.

An object of the present invention is to reduce the flow resistance in an exhaust gas system of an automotive vehicle. According to the invention, an exhaust system for an internal combustion engine mounted in an automotive vehicle comprises a funnel-shaped air duct having a forward wide end for admitting oncoming outside air into the duct during vehicle travel and a rearward narrow end for discharging the air into a tail portion of the exhaust gas system. The velocity of the air increases when the air is forced through the narrowing duct. The high velocity air will be injected into a tail portion of the exhaust system from a narrow end of the air duct. The injected high velocity air will entrain and increase the flow of slower velocity exhaust gases entering the tail portion. The result is a decreasing back pressure upstream in the exhaust system to thereby improve engine efficiency.

In the embodiment diagrammatically shown on the figure, an exhaust gas...