From f3403e76d1af178a004f522c14ea6156b940059c Mon Sep 17 00:00:00 2001 From: gPauls-TUHH <gerrit.pauls@tuhh.de> Date: Mon, 17 Mar 2025 15:18:41 +0100 Subject: [PATCH] Update for LG outputs --- .../mission_analysis/getting_started.md | 46 ++++++++++++++++++- 1 file changed, 45 insertions(+), 1 deletion(-) diff --git a/docs/documentation/analysis/mission_analysis/getting_started.md b/docs/documentation/analysis/mission_analysis/getting_started.md index dfb3d21..2059dd0 100644 --- a/docs/documentation/analysis/mission_analysis/getting_started.md +++ b/docs/documentation/analysis/mission_analysis/getting_started.md @@ -37,6 +37,8 @@ If everything is set up correctly, your first `design_mission` should land a few Due to many dependencies between the [sizing tools](../../sizing/index.md), performance data and component parameters are quite off within the first iteration. This can lead to an unstable aircraft configuration that will fail the `design_mission` (e.g. wrongly sized engines can't climb to the initial cruise altitude). To avoid this, the [low-fidelity 3D Standard Mission](methods.md/#lowfi) (`design_mission::breguet`) is triggered if no previous mission calculation can be found. Unlike the ordinary mission calculation, this sub-version of the `design_mission` finishes after a rough estimation of the fuel consumption. Once this method is finished, the `masses_cg_inertia/maximum_takeoff_mass/mass_properties/mass` node is updated and this block is written into the [Aircraft Exchange File](#acxml): +### XML output {#first_iterations_xml} + ```xml <mission description="Mission data" tool_level="0"> <design_mission description="Data of design mission"> @@ -117,6 +119,7 @@ Due to many dependencies between the [sizing tools](../../sizing/index.md), perf After the initial loop, we expect a robuster behavior which we can use to calculate the flight segments with an increased resolution. To achieve this, every segment is split into little time and way increments (only a few seconds/meters per increment) aiming for the trajectory points that were written into the `mission file`. In each increment, all relevant parameters are saved into a `mission profile`. After the calculation is done, said `mission profile` is exported as a [CSV file](#csv_file) into the `mission_data` directory. Within the [Aircraft Exchange File](#acxml) the `masses_cg_inertia/maximum_takeoff_mass/mass_properties/mass` node is updated when calculating a `design_mission`; for a `study_mission` it's the `mission/study_mission/takeoff_mass` node. Having a higher resolution also increases the amount of data in the `mission` block: +### XML output {#further_iterations_xml} ```xml <mission description="Mission data" tool_level="0"> @@ -309,6 +312,46 @@ After the initial loop, we expect a robuster behavior which we can use to calcul </cruise_step> </cruise_steps> </cruise> + <takeoff_performance_parameters description="Performance parameters for takeoff steps from 0 ft to screen height (35 ft)."> + <lift_off_speed description="Speed at lift-off"> + <value>65</value> + <unit>m/s</unit> + <lower_boundary>0</lower_boundary> + <upper_boundary>350</upper_boundary> + </lift_off_speed> + <takeoff_stall_speed description="Stall speed until screen height (35 ft)"> + <value>55</value> + <unit>m/s</unit> + <lower_boundary>0</lower_boundary> + <upper_boundary>350</upper_boundary> + </takeoff_stall_speed> + <lift_off_coefficient description="Lift coefficient at lift-off"> + <value>2.0</value> + <unit>1</unit> + <lower_boundary>0</lower_boundary> + <upper_boundary>100</upper_boundary> + </lift_off_coefficient> + <lift_off_angle_of_attack description="Angle of attack at lift-off"> + <value>0.15</value> + <unit>rad</unit> + <lower_boundary>0</lower_boundary> + <upper_boundary>1.57</upper_boundary> + </lift_off_angle_of_attack> + <takeoff_climb_angle description="Climb angle towards screen height (35 ft)"> + <value>0.15</value> + <unit>rad</unit> + <lower_boundary>0</lower_boundary> + <upper_boundary>1.57</upper_boundary> + </takeoff_climb_angle> + </takeoff_performance_parameters> + <landing_performance_parameters description="Performance parameters for landing steps from 50 ft to touchdown."> + <maximum_landing_angle_of_attack description="Maximum angle of attack while landing (between 50 ft and touchdown)"> + <value>0.15</value> + <unit>rad</unit> + <lower_boundary>0</lower_boundary> + <upper_boundary>1.57</upper_boundary> + </maximum_landing_angle_of_attack> + </landing_performance_parameters> </design_mission> </mission> ``` @@ -450,6 +493,7 @@ Program Settings │ ├── Fidelity Level │ ├── Mission Type │ ├── Center Of Gravity Method + ├── Interpolate Polars ├── Rate Of Climb Switch └── Precision ├── Acceleration Increment @@ -473,7 +517,7 @@ In the `program_specific` node, you can specify if the specific air range (SAR) In `general` you can decide how the needed fuel is estimated and you can tell **mission_analysis** in which way it shall behave in different flight segments. -The `mode` node lets you choose the methods that are applied. Using the keyword `low`/`mid` you will trigger the low-fidelity/mid-fidelity version of the [Standard Mission](methods.md) method. It also has three sub-methods to differentiate between `design_mission`, `study_mission` and `requirements_mission` which can be selected in the `mission_type` node. Please mind that the low-fidelity method only accepts the `design_mission`. The `rate_of_climb_switch` will only affect the [Climb to Ceiling](mission_steps.md/#climb_to_ceiling_subparagraph) step of the `requirements_mission`. With this option, **mission_analysis** calculates the optimum rate of climb towards service ceiling. +The `mode` node lets you choose the methods that are applied. Using the keyword `low`/`mid` you will trigger the low-fidelity/mid-fidelity version of the [Standard Mission](methods.md) method. It also has three sub-methods to differentiate between `design_mission`, `study_mission` and `requirements_mission` which can be selected in the `mission_type` node. Please mind that the low-fidelity method only accepts the `design_mission`. After the first iteration, the [Weight and Balance tool](../weight_and_balance_analysis/index.md) delivers vectors containing center of gravity positions in addition to the aircraft mass (center of gravity shift due to defueling). To take that into account, you can activate `interpolate_polars`. For kerosene based propulsion, the effects are rather small, but once H2 is involved you should consider using it. Furthermore, the `rate_of_climb_switch` will only affect the [Climb to Ceiling](mission_steps.md/#climb_to_ceiling_subparagraph) step of the `requirements_mission`. With this option, **mission_analysis** calculates the optimum rate of climb towards service ceiling. Finally, in `precision` you can set the parameters which will define the before mentioned increments of your mission profile. -- GitLab