Liquid rocket engine cooling channels
A liquid rocket engine cools a thruster body by pumping propellant through cooling channels integrated in the thruster body between internal and external surfaces. One or more of the cooling channel surfaces has a variable depth along a thrust axis to mix propellant flow and destroy thermal stratification, such as a depth that varies with a repeated contiguous sinusoidal form along the thrust axis. Fuel passed through the cooling channels injects from the combustion chamber wall towards a central portion of the combustion chamber to cross impinge with oxygen injected at the combustion chamber head so that a toroidal vortex forms to enhance propellant mixing.
1. A liquid rocket engine comprising:
a thruster body having an exterior surface and an interior surface, the interior surface forming a combustion chamber, throat and nozzle aligned along a thrust axis;
an oxygen manifold interfaced with the combustion chamber to provide oxygen to the combustion chamber;
a fuel manifold interfaced with the combustion chamber to provide fuel to the combustion chamber, the fuel burning with the oxygen to release energy, the energy propelling exhaust from the combustion chamber through the throat and out the nozzle along the thrust axis to create thrust;
plural cooling channels integrated in the thruster body between the interior and exterior surfaces along the thrust axis; and
a pump forcing fuel through the plural cooling channels, the fuel receiving thermal energy from the thruster body interior surface and transferring the thermal energy to the thruster body exterior surface;
wherein the plural cooling channels each have an inner surface that defines a variable depth along the thrust axis in a circumferential orientation, the variable depth having a sinusoidal form of plural consecutive wavelengths, at least some of the plural cooling channels having convergent bifurcation and divergent bifurcation to pass through a reduced circumference of the nozzle.
2. The liquid rocket engine of claim 1 wherein the at least one cooling channel has an averse portion proceeding from the combustion chamber to the nozzle and a reverse portion interfaced with the averse portion, the reverse portion proceeding from the nozzle to the combustion chamber, the sinusoidal form integrated in the cooling channel along substantially all of the length of the averse and reverse portions.
3. The liquid rocket engine of claim 2 wherein the sinusoidal form is further located on a side of the at least one cooling channel proximate to the thruster body interior surface.
4. The liquid rocket engine of claim 2 wherein the sinusoidal form is further located on a side of the at least one cooling channel proximate to the thruster body exterior surface.
5. The liquid rocket engine of claim 1 wherein the at least one cooling channel has opposing inner surfaces defining a variable depth along the thrust axis, each opposing inner surface having the sinusoidal form of plural consecutive wavelengths.
6. The liquid rocket engine of claim 5 wherein the opposing inner surface each have the sinusoidal form in phase with the other opposing inner surface.
7. The liquid rocket engine of claim 5 wherein the opposing inner surfaces each have the sinusoidal form out of phase with the other opposing surface.
8. The liquid rocket engine of claim 1 wherein:
the thruster body has a circumference around the thrust axis;
the plural cooling channels are disposed about substantially all of the circumference; and
each of the plural cooling channels have at least one inner surface that defines the variable depth along substantially all of the length of the thrust body.
9. The liquid rocket engine of claim 8 wherein a wall between each adjacent of the plural cooling channels varies in a sinusoidal form of plural wavelengths along substantially all of the length of the thrust body.
10. The liquid rocket engine of claim 1 wherein the sinusoidal form has an amplitude of substantially twenty percent of an average of the variable depth and a wavelength of substantially ten times the average of the variable depth.
11. A method for managing thermal energy of a liquid rocket engine thruster body, the method comprising:
pumping propellant through plural cooling channels formed in the thruster body, the propellant receiving thermal energy from an interior wall of the thruster body and transferring the thermal energy to an exterior wall of the thruster body; and
mixing the propellant in the plural cooling channels by passing the propellant over consecutive wave patterns formed in at least the inner surface of each of the plural cooling channels, the mixing providing unsteady boundary layers in the propellant, the consecutive wave patterns having a circumferential orientation, at least some of the plural cooling channels having convergent bifurcation and divergent bifurcation to pass through a reduced circumference of the thruster body at a nozzle.
12. The method of claim 11 wherein the consecutive wave patterns comprise a sinusoidal form of plural wavelengths.
13. The method of claim 12 wherein the plural cooling channels have an average depth and the sinusoidal form has an amplitude of substantially twenty percent of the average depth and a wavelength of substantially 10 times the average depth.
14. The method of claim 12 wherein the consecutive wave patterns are formed on opposing sides of each cooling channel in phase with each other.
15. The method of claim 12 wherein the consecutive wave patterns are formed on opposing sides of each cooling channel out of phase with each other.
16. The method of claim 11 further comprising:
injecting the propellant from one or more of the plural cooling channels into the thruster body at a combustion chamber through an opening formed in the one or more of the plural cooling channels, the propellant injected directly through the opening.
17. A method for managing thermal energy of a liquid rocket engine thruster body, the method comprising:
pumping propellant through plural cooling channels formed in the thruster body, the propellant receiving thermal energy from an interior wall of the thruster body and transferring the thermal energy to an exterior wall of the thruster body; and
mixing the propellant in the plural cooling channels by passing the propellant over consecutive wave patterns formed in at least one surface of each of the plural cooling channels, the mixing providing unsteady boundary layers in the propellant;
wherein the consecutive wave patterns are formed on opposing sides of each cooling channel in phase with each other and having a circumferential orientation.