LIVEdataset aec-bench@releasetasks 552models 18last submission … · built …
civilboth

Flap Gate Headloss

Calculates energy loss through flap gates (tide gates / non-return valves) installed on stormwater outfalls using the orifice equation h = V^2/(2gCd^2). Determines the discharge coefficient from gate type, looks up unseating head from pipe diameter, and computes the effective capacity reduction compared to an open pipe. Used in drainage design to verify that outfall losses remain within acceptable limits for the catchment.

both: The model must reason numerically unaided.

Standards

Hydraulic referencesManufacturer data

Tags

civildeterministicdrainageflap-gateheadlossoutfall-hydraulics

How this task is generated

One template produces many comparable benchmark tasks while keeping the scoring contract fixed.

  1. 01

    Template

    The reusable contract shown on this page.

  2. 02

    Scenario

    An archetype and site context are sampled.

  3. 03

    Difficulty tier

    Inputs may be hidden at harder tiers.

  4. 04

    Task prompt

    The model responds with the declared outputs.

Parameters

Inputs the model receives, and the outputs it is scored on.

Inputs

4 inputs

Always given

Included directly in every task prompt.

3

  • Pipe diameter

    pipe_diameter_mm

    Nominal pipe diameter at the outfall

    150225300375450600750900+1

  • Flow velocity m per s

    flow_velocity_m_per_s

    Mean flow velocity in the outfall pipe V

    0.3 – 4 m/s

  • Upstream head

    upstream_head_m

    Upstream head driving flow through the gate

    0.1 – 3 m

Derived from scenario

Sampled from the scenario and inferable from its description.

1

  • Gate type

    gate_type

    Flap gate hinge configuration

    Derived from the archetype scenario. Hidden at hard difficulty.

    side_hingedtop_hingedduckbill

Scored outputs

4 outputs

Headloss

headloss_m

Energy loss through the flap gate (m)

Scores if within ±5% of the reference value.

Unseating head

unseating_head_m

Minimum head to open the gate against its own weight (m)

Scores if within ±1% of the reference value.

Capacity reduction

capacity_reduction_percent

Effective capacity reduction compared to open pipe (%)

Scores if within ±3% of the reference value.

Discharge coefficient

discharge_coefficient

Discharge coefficient Cd for the gate type

Scores if within ±3% of the reference value.

Difficulty

Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.

easy

All inputs given

All parameters given, common suburban gate and pipe size

medium

All inputs given

All parameters given, any gate type and pipe size

hard

Some inputs hidden

Gate type hidden, agent must infer from site description

Hidden inputs

  • Gate typegate_type

Prompt replacement text

The outfall uses a {{ archetype.description }} ({{ archetype.site_context }})

Task bundle

The exact instruction and parameter contract used to generate this task, pinned to the published library source.

/workspace

  • instruction.md

Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.

1You are a senior civil engineer specializing in stormwater drainage and outfall hydraulics.2 3## Problem4 5Calculate the energy loss through a flap gate (non-return valve) installed on a stormwater outfall. Determine the discharge coefficient, headloss, unseating head, and effective capacity reduction.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Pipe diameter | {{ pipe_diameter_mm }} | mm |12| Flow velocity (V) | {{ flow_velocity_m_per_s }} | m/s |13{% if gate_type is defined %}14| Gate type | {{ gate_type }} | - |15{% endif %}16| Upstream head | {{ upstream_head_m }} | m |17{% if archetype_description is defined %}18 19### Site Conditions20 21{{ archetype_description }}22{% endif %}23 24{% if tool_available %}25## Available Tool26 27A flap gate headloss calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:28 29```bash30python3 /workspace/{{ meta.name }}_calc.py --help31```32 33You may use this tool to verify your calculations or compute values directly.34{% endif %}35 36## Required37 38Calculate the following:39 401. Discharge coefficient Cd for the gate type412. Energy loss through the flap gate (m)423. Minimum unseating head to open the gate (m)434. Effective capacity reduction compared to an open pipe (%)44 45## Applicable Standards46 47- Manufacturer data (Waterman, Hydro Gate, Mosbaek)48- Hydraulic references for flap gate discharge coefficients49 50## Constraints51 52- No internet access is available. Work from engineering knowledge and the provided tool.53- Use the orifice-based headloss equation:54 55 **Headloss:** h_loss = V² / (2 × g × Cd²)56 57 where:58 - V = mean flow velocity in the pipe (m/s)59 - g = 9.81 m/s²60 - Cd = discharge coefficient (depends on gate type)61 62- Discharge coefficient ranges by gate type:63 - Side-hinged: Cd = 0.60 – 0.65 (use midpoint 0.625)64 - Top-hinged: Cd = 0.55 – 0.60 (use midpoint 0.575)65 - Duckbill (elastomeric): Cd = 0.50 – 0.55 (use midpoint 0.525)66 67- Unseating head lookup by pipe diameter:68 69 | Diameter (mm) | Unseating head (m) |70 |---------------|--------------------|71 | 150 | 0.010 |72 | 225 | 0.012 |73 | 300 | 0.015 |74 | 375 | 0.020 |75 | 450 | 0.025 |76 | 600 | 0.030 |77 | 750 | 0.035 |78 | 900 | 0.040 |79 | 1200 | 0.050 |80 81- **Capacity reduction:** capacity_reduction_percent = (1 − Cd) × 10082 83## Output Format84 85Show your step-by-step working in Markdown, including the discharge coefficient selection, headloss calculation, unseating head lookup, and capacity reduction determination. At the end of your solution, include a JSON block with your final answers in exactly this format:86 87```json88{89 "headloss_m": <numeric_value>,90 "unseating_head_m": <numeric_value>,91 "capacity_reduction_percent": <numeric_value>,92 "discharge_coefficient": <numeric_value>93}94```95 96Write your complete solution to `/workspace/output.md`.97

Scenario archetypes

Each generated task is drawn from one of these realistic scenario bands.

Site contexts ground each scenario in a real locale the model can use to infer hidden values.

Suburban stormwater

suburban_stormwater

Suburban stormwater outfall with side-hinged flap gate

sydney-suburban-outfallbrisbane-creek-outfall
Parameter ranges
pipe_diameter_mm
300, 375, 450, 600
flow_velocity_m_per_s
0.5 – 2
upstream_head_m
0.2 – 1.5
gate_type
side_hinged

Tidal outfall

tidal_outfall

Tidal outfall with top-hinged flap gate to prevent saltwater intrusion

melbourne-tidal-creekgold-coast-canal-outfall
Parameter ranges
pipe_diameter_mm
450, 600, 750, 900, 1200
flow_velocity_m_per_s
0.8 – 3
upstream_head_m
0.3 – 2.5
gate_type
top_hinged

Small lot drainage

small_lot_drainage

Small lot or car park drainage outfall with duckbill elastomeric valve

perth-carpark-outfalladelaide-lot-drain
Parameter ranges
pipe_diameter_mm
150, 225, 300
flow_velocity_m_per_s
0.3 – 1.5
upstream_head_m
0.1 – 0.8
gate_type
duckbill

Trunk drainage

trunk_drainage

Trunk stormwater outfall with heavy-duty top-hinged flap gate

darwin-trunk-outfallcairns-coastal-outfall
Parameter ranges
pipe_diameter_mm
750, 900, 1200
flow_velocity_m_per_s
1 – 4
upstream_head_m
0.5 – 3
gate_type
top_hinged

Example task

sydney-suburban-outfall-suburban-stormwater-preview — hard difficulty, some inputs hidden.

Suburban stormwater outfall with side-hinged flap gate. sydney-suburban-outfall. Required outputs: headloss_m, unseating_head_m, capacity_reduction_percent, discharge_coefficient

The model sees

Scenario context and visible inputs.

pipe_diameter_mm
300 mm
flow_velocity_m_per_s
0.5 to 2 m/s
upstream_head_m
0.2 to 1.5 m

Executable tool: flap-gate-headloss_calc.py

The model must infer

Inputs withheld at this difficulty.

  • Gate type

    gate_type

Stand-in text in the prompt

The outfall uses a {{ archetype.description }} ({{ archetype.site_context }})

The model must produce

The scored JSON answer schema.

{
  "headloss_m": <number>,
  "unseating_head_m": <number>,
  "capacity_reduction_percent": <number>,
  "discharge_coefficient": <number>
}
  • headloss_m · scored within ±5%
  • unseating_head_m · scored within ±1%
  • capacity_reduction_percent · scored within ±3%
  • discharge_coefficient · scored within ±3%