White Dwarf Combustion Chamber - Revision history

Dug20: /* Nozzle */

2022-08-14T00:20:47Z

Nozzle

← Older revision		Revision as of 00:20, 14 August 2022
Line 42:		Line 42:
	The nozzle is made of graphite, and was manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.		The nozzle is made of graphite, and was manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.

	Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page]. Extra 'samples' of the graphite-helicoil threads, separate from the nozzle, ~~were ordered~~ so they could be tested until failure experimentally. This provided useful data to ensure that the threads on the nozzle were not overtightened and damaged when it came to tightening bolts into them.		Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page]. Extra 'samples' of the graphite-helicoil threads were ordered, separate from the nozzle, so they could be tested until failure experimentally. This provided useful data to ensure that the threads on the nozzle were not overtightened and damaged when it came to tightening bolts into them.

	==Retainer Ring==		==Retainer Ring==

Dug20: /* Nozzle */

2022-08-14T00:20:24Z

Nozzle

← Older revision		Revision as of 00:20, 14 August 2022
Line 42:		Line 42:
	The nozzle is made of graphite, and was manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.		The nozzle is made of graphite, and was manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.

	Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].		Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page]. Extra 'samples' of the graphite-helicoil threads, separate from the nozzle, were ordered so they could be tested until failure experimentally. This provided useful data to ensure that the threads on the nozzle were not overtightened and damaged when it came to tightening bolts into them.

	==Retainer Ring==		==Retainer Ring==

Dug20: /* Nozzle */

2022-08-14T00:19:14Z

Nozzle

← Older revision		Revision as of 00:19, 14 August 2022
Line 40:		Line 40:

	== Nozzle==		== Nozzle==
	The nozzle is made of graphite, and ~~is intended to be~~ manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.		The nozzle is made of graphite, and was manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.

	Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].		Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].

Dug20: /* Water Pump */

2022-08-14T00:18:53Z

Water Pump

← Older revision		Revision as of 00:18, 14 August 2022
Line 28:		Line 28:
	The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it may be possible for the nozzle to transfer sufficient heat to the metal components to damage them, if they were left uncooled.		The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it may be possible for the nozzle to transfer sufficient heat to the metal components to damage them, if they were left uncooled.

	The pump used is a Pentax CR 75, 230 V single-phase electric pump, ~~to provide~~ just under 1 kg/s of water flow rate.		The pump used is a Pentax CR 75, 230 V single-phase electric pump, which provides just under 1 kg/s of water flow rate (measured experimentally).

	==Copper Chamber==		==Copper Chamber==

Dug20 at 00:18, 14 August 2022

2022-08-14T00:18:10Z

← Older revision		Revision as of 00:18, 14 August 2022
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	== Overview ==		== Overview ==
	The [[White Dwarf]] combustion chamber uses a water-cooled jacket, with a graphite nozzle. The cooling channels are cut into an off-the-shelf copper tube using a CNC machine. The outer walls of the cooling jacket are made of stainless steel and are welded together.		The [[White Dwarf]] combustion chamber uses a water-cooled jacket, with a graphite nozzle. The cooling channels are cut into an off-the-shelf copper tube using a CNC machine. The outer walls of the cooling jacket are made of stainless steel and are welded together.
	[[File:Combustion Chamber Assembly Summary.png\|thumb\|700x700px\|Cutaway of the White Dwarf combustion chamber ~~CAD (without~~ the ~~injector)~~.]]		[[File:Combustion Chamber Assembly Summary.png\|thumb\|700x700px\|Cutaway of the White Dwarf combustion chamber, with key components labelled. This image is taken from the [[:File:COMBUSTION CHAMBER ASSEMBLY.pdf\|overall assembly drawing]].]]

	=== Resources ===		=== Resources ===

Dug20: /* Water Pump */

2022-08-14T00:17:12Z

Water Pump

← Older revision		Revision as of 00:17, 14 August 2022
Line 26:		Line 26:

	== Water Pump ==		== Water Pump ==
	The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it may be possible for the nozzle to transfer sufficient heat to the metal components to damage them.		The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it may be possible for the nozzle to transfer sufficient heat to the metal components to damage them, if they were left uncooled.

	The pump used is a Pentax CR 75, 230 V single-phase electric pump, to provide just under 1 kg/s of water flow rate.		The pump used is a Pentax CR 75, 230 V single-phase electric pump, to provide just under 1 kg/s of water flow rate.

Dug20: /* Overview */

2022-08-14T00:16:53Z

Overview

← Older revision		Revision as of 00:16, 14 August 2022
Line 26:		Line 26:

	== Water Pump ==		== Water Pump ==
	The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it ~~would~~ be possible for the nozzle to transfer sufficient heat to the metal components to damage them.		The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it may be possible for the nozzle to transfer sufficient heat to the metal components to damage them.

	The pump used is a Pentax CR 75, 230 V single-phase electric pump, to provide just under 1 kg/s of water flow rate.		The pump used is a Pentax CR 75, 230 V single-phase electric pump, to provide just under 1 kg/s of water flow rate.

Dug20: /* Retainer Ring */

2022-08-14T00:16:04Z

Retainer Ring

← Older revision		Revision as of 00:16, 14 August 2022
Line 46:		Line 46:
	==Retainer Ring==		==Retainer Ring==

	The retainer ring is manufactured from a single large piece of stainless steel billet. It has an inlet for the water coolant, and is brazed to the copper jacket, and welded to the rest of the steel components.		The retainer ring is manufactured from a single large piece of stainless steel billet. It has an inlet for the water coolant, and is brazed to the copper jacket, and welded to the rest of the steel components.

			Triangular gusset plates were added between the retainer ring and the steel outer tube, after an FEA analysis revealed a stress concentration at original (circumferential) weld point between the two. The gussets are intended to increase the weld length and reduce the risk of failure, which would arise from the combustion chamber pressure pushing the nozzle against the retainer ring.

	==Steel Outer Tube==		==Steel Outer Tube==

Dug20: /* Engineering Drawings */

2022-08-14T00:10:25Z

Engineering Drawings

← Older revision		Revision as of 00:10, 14 August 2022
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	== Overview ==		== Overview ==
	The White Dwarf combustion chamber uses a water-cooled jacket, with a graphite nozzle. The cooling channels are cut into an off-the-shelf copper tube using a CNC machine. The outer walls of the cooling jacket are made of stainless steel and are welded together.		The [[White Dwarf]] combustion chamber uses a water-cooled jacket, with a graphite nozzle. The cooling channels are cut into an off-the-shelf copper tube using a CNC machine. The outer walls of the cooling jacket are made of stainless steel and are welded together.
	[[File:Combustion Chamber Assembly Summary.png\|thumb\|700x700px\|Cutaway of the White Dwarf combustion chamber CAD (without the injector).]]		[[File:Combustion Chamber Assembly Summary.png\|thumb\|700x700px\|Cutaway of the White Dwarf combustion chamber CAD (without the injector).]]

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	=== Engineering Drawings ===		=== Engineering Drawings ===
	A. Overall Assembly		A. [[:File:COMBUSTION CHAMBER ASSEMBLY.pdf\|Overall Assembly]]

	1. [[:File:WHITE DWARF CHAMBER.pdf\|Copper Chamber]]		1. [[:File:WHITE DWARF CHAMBER.pdf\|Copper Chamber]]
Line 15:		Line 15:
	2. [[:File:WHITE DWARF NOZZLE.pdf\|Nozzle]]		2. [[:File:WHITE DWARF NOZZLE.pdf\|Nozzle]]

	3. Steel Outer Tube		3. [[:File:STEEL OUTER WALL.pdf\|Steel Outer Tube]]

	4. Coolant Inlet Closure Ring		4. [[:File:COMBUSTION CHAMBER ASSEMBLY.pdf\|Coolant Inlet Closure Ring]]

	5. [[:File:WHITE DWARF RET RING.pdf\|Retainer Ring]]		5. [[:File:WHITE DWARF RET RING.pdf\|Retainer Ring]]

	8. Outlet Ring		8. [[:File:OUTLET RING TO GEOMIQ.pdf\|Outlet Ring]]

			9. [[:File:INJECTOR ENDCAP WITH SLOT.pdf\|Injector Face / Test Stand Mount]]

			== Water Pump ==
			The engine uses an electric water pump to feed the cooling jacket, on a closed loop system. The water that leaves the cooling jacket returns to a main reservoir, where it is recycled so that the cooling jacket can operate indefinitely. This is useful for cooling the combustion chamber, and especially the nozzle, after engine shutdown, since the nozzle may act as a large heatsink. Post-shutdown, it would be possible for the nozzle to transfer sufficient heat to the metal components to damage them.

			The pump used is a Pentax CR 75, 230 V single-phase electric pump, to provide just under 1 kg/s of water flow rate.

	==Copper Chamber==		==Copper Chamber==
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	*		*

	Made of copper due to it's high thermal conductivity, which significantly reduces the thermal stress across the walls as well as the wall temperatures. If steel was used, the thermal stresses would be much higher (and would outweigh the gain received from steel's higher yield stress).		Made of copper due to it's high thermal conductivity, which significantly reduces the thermal stress across the walls as well as the wall temperatures. If steel was used, the thermal stresses would be much higher, and would outweigh the gain received from steel's higher yield stress.

	Temperature and pressure drop predictions were generated using Bamboo, and the results are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].		Temperature and pressure drop predictions were generated using Bamboo, and the results are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].
Line 33:		Line 40:

	== Nozzle==		== Nozzle==
	The nozzle is made of graphite, and is intended to be manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].		The nozzle is made of graphite, and is intended to be manufactured by [http://en.tokaicarbon.eu/ Tokai Carbon Europe]. It contains 16 holes that will contain M5 x '3D' [https://www.stanleyengineeredfastening.com/brands/optia/heli-coil helicoil] inserts, allowing the nozzle to be pulled into the retaining ring, whilst simultaneously compressing the graphite gasket in between the nozzle and retainer ring. This graphite gasket is used to seal the leak path between the nozzle and retainer ring.

			Graphite thread failure calculations are available on the [https://github.com/cuspaceflight/White-Dwarf-Cooling simulations GitHub page].

	==Retainer Ring==		==Retainer Ring==

	The retainer ring is manufactured from a single large piece of stainless steel billet. It has an inlet for the water coolant, and is ~~intended to be~~ brazed to the copper jacket, and welded to the rest of the steel components.		The retainer ring is manufactured from a single large piece of stainless steel billet. It has an inlet for the water coolant, and is brazed to the copper jacket, and welded to the rest of the steel components.

	~~==Distribution Ring Front==~~		==Steel Outer Tube==
	~~The flat ring that encloses the inlet distribution ring is intended to be a water-jet cut piece of stainless steel. It will be welded to the steel tube and the retainer ring.~~

	==Steel Tube==
	The steel tube that encloses the copper fins will slide over the copper, and is not connected to the copper directly. It is intended to be a custom-made welded stainless steel tube, manufactured in the Dyson centre.		The steel tube that encloses the copper fins will slide over the copper, and is not connected to the copper directly. It is intended to be a custom-made welded stainless steel tube, manufactured in the Dyson centre.

	== ~~Water Pump~~ ==		==Outlet Ring==
	The ~~engine uses an electric water pump to feed~~ the ~~cooling jacket, on a closed loop system. The~~ water ~~that leaves~~ the ~~cooling jacket returns~~ to ~~a main reservoir, where~~ it ~~is recycled so~~ that the ~~cooling jacket can operate indefinitely~~.		The coolant outlet ring increases the water flow area from the channels to the circumferential path it that must be taken to reach the outlet pipe. This increased flow area reduces the flow velocity, thus reduces pressure losses in the coolant outlet ring.

	~~==Injector Connection==~~
	~~Not yet designed. The injector-end flange is designed to connect to both~~ the ~~injector and~~ the ~~test stand~~.

	~~===Notes ===~~

	*The outlet ~~distribution~~ ring ~~needs~~ to ~~have a larger flow cross section, as right now it is very narrow, which causes very large pressure drops as~~ the ~~coolant tries~~ to ~~leave it~~. ~~This would also cause uneven velocity distributions in the coolant channel, as the pressure would vary significantly around~~ the outlet ~~distribution~~ ring.		The outlet ring also contains 19 x M4 through-holes, to enable the injector face to be pulled against the outlet ring. A graphite gasket is present between the injector face and outlet ring to prevent combustion gas leaking out of that leak path.

Dug20: /* Engineering Drawings */

2022-08-13T23:58:13Z

Engineering Drawings

← Older revision		Revision as of 23:58, 13 August 2022
Line 1:		Line 1:
	== Overview ==		== Overview ==
	The White Dwarf combustion chamber uses a water-cooled jacket, with a graphite nozzle. The cooling channels are cut into an off-the-shelf copper tube using a CNC machine. The outer walls of the cooling jacket are made of stainless steel and are welded together.		The White Dwarf combustion chamber uses a water-cooled jacket, with a graphite nozzle. The cooling channels are cut into an off-the-shelf copper tube using a CNC machine. The outer walls of the cooling jacket are made of stainless steel and are welded together.
			[[File:Combustion Chamber Assembly Summary.png\|thumb\|700x700px\|Cutaway of the White Dwarf combustion chamber CAD (without the injector).]]
	[[File:~~White dwarf chamber labelled~~.png\|thumb\|Cutaway of the White Dwarf combustion chamber CAD (without the injector).]]

	=== Resources ===		=== Resources ===
Line 10:		Line 9:

	=== Engineering Drawings ===		=== Engineering Drawings ===
			A. Overall Assembly

			1. [[:File:WHITE DWARF CHAMBER.pdf\|Copper Chamber]]

			2. [[:File:WHITE DWARF NOZZLE.pdf\|Nozzle]]

			3. Steel Outer Tube

			4. Coolant Inlet Closure Ring

			5. [[:File:WHITE DWARF RET RING.pdf\|Retainer Ring]]

	* [[:File:WHITE DWARF CHAMBER.~~pdf\|Copper Chamber]]~~		8. Outlet Ring
	* [[:File:WHITE DWARF NOZZLE.pdf\|Nozzle]]
	* [[:File:WHITE DWARF RET RING.pdf\|Retainer Ring]]

	==Copper Chamber==		==Copper Chamber==