Article

Boundary-Layer Meteorology

, Volume 113, Issue 3, pp 427-459

First online:

A comparison of wind-tunnel experiments and numerical simulations of neutral and stratified flow over a hill

  • A.N. RossAffiliated withInstitute for Atmospheric Science, School of the Environment, University of Leeds Email author 
  • , S. ArnoldAffiliated withInstitute for Atmospheric Science, School of the Environment, University of Leeds
  • , S.B. VosperAffiliated withMet Office
  • , S. D. MobbsAffiliated withInstitute for Atmospheric Science, School of the Environment, University of Leeds
  • , N. DixonAffiliated withInstitute for Atmospheric Science, School of the Environment, University of Leeds
  • , A. G. RobinsAffiliated withSchool of Engineering, University of Surrey

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

A comparison is made of numerical and experimental results for flow over two-dimensional hills in both neutral and stably stratified flow. The numerical simulations are carried out using a range of one-and-a-half order and second-order closure schemes. The performance of the various turbulence schemes in predicting both the mean and turbulent quantities over the hill is assessed by comparing the results with new wind-tunnel measurements. The wind-tunnel experiments include both neutral and stably stratified flow over two different hills with different slopes, one of which is steep enough to induce flow separation. The dataset includes measurements of the mean and turbulent parts of the flow using laser Doppler anemometry. Pressure measurements are also made across the surface of the hill. These features make the dataset an excellent test of the model performance. In general second-order turbulence schemes provide the best agreement with the experimental data, however, they can be numerically unstable for steep hills. Some modifications can be made to the standard one-and-a-half order closure scheme, which results in improved performance at a fraction of the computation cost of the second-order schemes.

Keywords

Boundary layer Hill Stable stratification Turbulent closure Wind tunnel.