Cơ chế giảm lực cản trên một phương tiện vuông gốc tổng quát bằng cách sử dụng khoang cơ sở tối ưu không nhạy cảm với góc nghiêng
Tóm tắt
Các quy định về phát thải khí nhà kính toàn cầu đang thúc đẩy sự phát triển của các phương tiện chở khách tiết kiệm năng lượng hơn. Một trong những yếu tố chính ảnh hưởng đến mức tiêu thụ năng lượng là lực cản khí động học, trong đó một phần lớn của lực cản liên quan đến dòng chảy dưới cơ sở. Các điều kiện môi trường như gió có thể làm tăng lực cản liên quan đến dòng chảy bị tách ra ở cơ sở. Bài báo này nghiên cứu về một khoang cơ sở tối ưu không nhạy cảm với góc nghiêng trên một phương tiện vuông gốc trong điều kiện gió chéo ổn định. Đối tượng thử nghiệm là một mô hình hình khối đơn giản, hình dạng Windsor, có bánh xe. Mô hình được thử nghiệm thực nghiệm với một khoang thẳng và một khoang thu hẹp. Các góc thu hẹp đã được tối ưu hóa về mặt số để cải thiện khả năng chống lại gió bên liên quan đến lực cản. Áp suất cơ sở và hình ảnh động lực học hạt tiểu sinh học của toàn bộ dòng chảy được đo trong hầm gió. Kết quả cho thấy một khoang làm giảm dòng chảy chéo trong dòng chảy, tăng áp suất cơ sở, do đó giảm lực cản. Việc tối ưu hóa thêm việc thu hẹp khoang còn làm giảm thêm dòng chảy chéo và tạo ra một dòng chảy nhỏ hơn với ít tổn thất hơn. Tổng thể, sự không ổn định của dòng chảy giảm nhờ khoang bằng cách giảm thiểu sự khuếch tán trong các lớp cắt cũng như làm giảm chuyển động của dòng chảy. Tuy nhiên, những chuyển động dòng chảy có trật tự, biểu thị cho một dòng chảy cân bằng, lại gia tăng nhờ vào các khoang được nghiên cứu.
Từ khóa
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