Restrictors using the Venturi effect
Restrictors are disclosed that include a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof, and with the converging inlet cone and the diverging outlet cone each defining an inner passageway that transitions as a hyperbolic or parabolic function toward the throat.
1. A restrictor comprising:
a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof;
wherein the converging inlet cone and the diverging outlet cone each define an inner passageway that transitions as a hyperbolic or parabolic function toward the throat;
wherein the inner passageway of the inlet cone and the inner passageway of the outlet cone both transition as a parabolic function toward the throat, and a length of the converging inlet cone and a length of the diverging outlet cone have a ratio in the range of 1:3 to 1:5.
2. A system comprising:
an engine that is naturally aspirated or boosted;
restrictor comprising a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof; wherein the converging inlet cone and the diverging outlet cone each define an inner passageway that transitions as a hyperbolic or parabolic function toward the throat;
a first component in fluid communication with the inlet cone of the restrictor; a second component in fluid communication with the outlet cone of the restrictor;
wherein, during operation of the system, a pressure drop occurs between the first component and the second component;
wherein the inner passageway of the inlet cone and the inner passageway of the outlet cone both transition as a parabolic function toward the throat, and a length of the converging inlet cone and a length of the diverging outlet cone have a ratio in the range of 1:3 to 1:5.
3. The system of claim 2 , wherein the first component is a crankcase and the fluid in fluid communication with the inlet cone is blowby gas.
4. The system of claim 3 , wherein the second component is an air intake manifold of an engine.
5. The system of claim 3 , wherein the second component is a compressor of a turbocharger.
6. A system comprising:
an engine that is naturally aspirated or boosted;
a restrictor comprising a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof; wherein the converging inlet cone and the diverging outlet cone each define an inner passageway that transitions as a hyperbolic or parabolic function toward the throat;
a first component in fluid communication with the inlet cone of the restrictor; a second component in fluid communication with the outlet cone of the restrictor;
wherein, during operation of the system, a pressure drop occurs between the first component and the second component;
wherein the inner passageway of the inlet cone and the inner passageway of the outlet cone both transition as a hyperbolic function toward the throat, and a length of the converging inlet cone and a length of the diverging outlet cone have a ratio in the range of 1:5 to 1:8.
7. The system of claim 6 , wherein the first component is a crankcase and the fluid in fluid communication with the inlet cone is blowby gas.
8. The system of claim 7 , wherein the second component is an air intake manifold of an engine.
9. The system of claim 7 , wherein the second component is a compressor of a turbocharger.
10. The system of claim 6 , wherein the ratio is in the range of 1:6 to 1:8.
11. The system of claim 6 , wherein the inlet cone begins with a rounded chamfer directing fluid flow into the inlet cone.
12. The system of claim 6 , wherein the outlet cone terminates with a rounded chamfer directing fluid flow out of the outlet cone.
13. A restrictor comprising:
a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof;
wherein the converging inlet cone has an entrance defining a circular opening and the inlet cone begins with a rounded chamfer directing fluid flow into the inlet cone;
wherein the converging inlet cone and the diverging outlet cone each define an inner passageway that transition as a hyperbolic function toward the throat or as a parabolic function toward the throat;
wherein each hyperbolic or parabolic function has flow lines at the throat that are parallel to one another, thereby providing a constant rate of flow through the restrictor without creating a vena contracta;
wherein the throat is a junction of the end of the converging inlet cone with a beginning of the outlet cone, thereby having no length,
wherein the outlet cone terminates with a rounded chamfer directing fluid flow out of the outlet cone.
14. A restrictor comprising:
a body defining a Venturi tube having a throat defining a junction of a converging inlet cone to a diverging outlet cone along a longitudinal axis thereof;
wherein the converging inlet cone has an entrance defining a circular opening, and the converging inlet cone and the diverging outlet cone each define an inner passageway that transition as a hyperbolic function toward the throat or as a parabolic function toward the throat;
wherein each hyperbolic or parabolic function has flow lines at the throat that are parallel to one another, thereby providing a constant rate of flow through the restrictor without creating a vena contracta;
wherein the throat is a junction of the end of the converging inlet cone with a beginning of the outlet cone, thereby having no length; and
wherein the throat has a diameter that is less than 1 mm and a length of the outlet cone is in the range of 20 mm to 90 mm.
15. The restrictor of claim 14 , wherein the inner passageway of the inlet cone and the inner passageway of the outlet cone both transition as a hyperbolic function toward the throat, and a length of the converging inlet cone and a length of the diverging outlet cone have a ratio in the range of 1:5 to 1:8.
16. The restrictor of claim 15 , wherein the ratio is in the range of 1:6 to 1:8.
17. The restrictor of claim 14 , wherein the inner passageway of the inlet cone and the inner passageway of the outlet cone both transition as a parabolic function toward the throat, and a length of the converging inlet cone and a length of the diverging outlet cone have a ratio in the range of 1:3 to 1:5.
18. The restrictor of claim 14 , wherein the inlet cone begins with a rounded chamfer directing fluid flow into the inlet cone.
19. The restrictor of claim 18 , wherein the outlet cone terminates with a rounded chamfer directing fluid flow out of the outlet cone.
20. The restrictor of claim 14 , wherein the inlet cone has a non-circular geometry when viewed as a cross-section transverse to the longitudinal axis.
21. The restrictor of claim 20 , wherein the non-circular geometry is rectangular.
22. The restrictor of claim 20 , wherein the outlet cone has a non-circular geometry when viewed as a cross-section transverse to the longitudinal axis.